The Peter Attia Drive - The impact of stress on our physical and emotional health | Robert Sapolsky, Ph.D. (#51 rebroadcast)

Episode Date: April 24, 2023

View the Show Notes Page for This Episode Become a Member to Receive Exclusive Content Sign Up to Receive Peter’s Weekly Newsletter In this episode, Robert Sapolsky, Ph.D., discusses the widespread impact of stress on our physical and emotional health as well as the mechanisms by which it can precipitate chronic illness, dementia, depression, and more. He also provides insight into the factors that contribute to the stress response (and our ability to handle it) such as social rank, personality, environment, and genetics. Lastly, we discuss how our behavior is altered in the face of stress and how that not only has a pervasive effect on a personal level, but also on society as a whole in how we interact with each other. We discuss: Background, interest in stress, and Robert’s time in Kenya studying baboons [2:45]; Physiology of a stress response, and why it’s ingrained in our DNA [9:45]; Individual variation in the response to stress, and how everyone has a different optimal level [19:45]; How social rank and personality differences affect our stress response [26:30]; What’s happening in the brain when faced with stressful situations? [35:00]; What makes the human brain different than all other species? [44:15]; Imprinting stress to your kids epigenetically [48:00]; The role of stress on memory and the consequences of hypercortisolemia [53:00]; The impact of subjective socioeconomic status and social media on stress levels and health [57:45]; Tips for managing stress in the modern world [1:13:15]; What Robert learned about himself studying the social behavior of baboons [1:25:30]; The multilayered factors behind every human behavior, the context of “good and bad”, and exploring the human capacity of the wild extremes of violence and altruism from moment to moment [1:30:15]; PMS: How two women with identical hormone levels can have completely different emotional experiences [1:34:45]; How much of a role do genes play in depression and other emotional states? [1:38:00]; Why is cortisol elevated under sleep deprivation? [1:46:00]; The impact of stress on cancer [1:50:30]; The impact of stress on atherosclerosis, dementia, addiction, and depression [1:57:00]; Impulsiveness, impaired judgment, and lack of empathy in times of stress [2:01:45]; What advice would Robert give his 25-year-old self? [2:08:45]; and More. Connect With Peter on Twitter, Instagram, Facebook and YouTube

Hey everyone, welcome to the Drive Podcast. I'm your host, Peter Atia. This podcast, my website, and my weekly newsletter, I'll focus on the goal of translating the science of longevity into something accessible for everyone. Our goal is to provide the best content in health and wellness, full stop, and we've assembled a great team of analysts to make this happen. If you enjoy this podcast, we've created a membership program that brings you far more in-depth content if you want to take your knowledge of this space to the next level. At the end of this episode, I'll explain

what those benefits are, or if you want to learn more now, head over to peteratia MD dot com forward slash subscribe. Now, without further delay, here's today's episode. Welcome to another special episode of The Drive. For this week's episode, we're going to re-broadcast my conversation with Robert Sapolsky, which was originally released back in April of 2019, about four years ago. Many of you may recognize that name because Robert has written some incredible books, including the very popular, Why Zebras Don't Get Alcers, A Guide to Stress, Stress-Related Disease, and Coping.

I had first seen Robert speak about a year and a half prior to my interview with him, and I remember thinking during his talk, this is the first time I'm really being convinced of the true pathology of stress. You know, I think prior to that, I'd always heard the old adage that stress could kill you, but I kind of dismissed it as, yeah, yeah, yeah, and we used to think that stress caused ulcers, but then we found out it was H. Pylori, et cetera, et cetera. But the way Robert spoke about it, I really began to pay more attention to it, which of course led to me reading up on this more.

And at that point, I just decided I needed to meet Robert. Robert's work, in particular, his presentation that day, got me to think about the molecular and physiologic harm of hypercordisolemia in particular. In my conversation with Robert, we spoke a great deal about that, but we also talked about things outside of them. We talked about the role of depression, what the impact is of stress on the developing brain, and also on the brain later in life. And even on areas where the relationship between stress and disease is not that well understood yet, that clearly came across in our discussion of cancer. Robert is a professor of biology,

of neurobiology, and of neurosurgery at Stanford. He's also a MacArthur fellow in 1987. He was awarded the fellowship, which some of you may recognize by its other name, the Genius Grant, something I consider very appropriate for a man of Robert's talents. Overall, I found this discussion riveting, and I hope to speak with Robert again, but for now, I hope you'll enjoy revisiting this discussion as much as I did. So without further delay, please enjoy or re-enjoy my conversation with the wonderful Robert Cipalski. Robert, thank you so much for making the time to meet with me today on a lovely, rainy

San Francisco afternoon. Sure, glad to be indoors here. As I was saying earlier, we had met once before really briefly, so briefly that you would not remember it, and of course, only I would. Summer of 17, I believe you were giving a talk in Sun Valley and I was there and you gave a talk on stress. Now, it was to a lay audience. So you didn't really get to go into the depth. And I remember sitting in the audience thinking, oh, you know, a lot of what he's saying is really starting to make sense to me.

And I can't wait to get a little deeper into this stuff because truthfully, and I'm just going to open with sort of my meoculpa, you've always heard people say stress kills. And I got to be honest with you. I always thought that was sort of nonsense. I was like, come on. What do you mean stress kills? Stress is good. It builds resilience.

Oh, what is the mechanism by which stress, stress kills? Stress is good, it builds resilience, blah, blah, blah. What is the mechanism by which stress quote unquote kills? But of course, once you start to understand the endocrine system and of course training is a surgeon and not an endocrinologist, I sort of missed out on that, you start to see it. And in that talk, you admittedly at a sort of high level for the audience really walked through the danger of hypercordislemia. And so in many ways, I guess a year and a half ago was really when I became a fan of your

work and then kind of said, you know what, there is something to this. So anyway, with that, I appreciate you taking this time. Sure. And just to sort of back off a bit from that, I actually don't think stress kills you out right very often, but it sure makes other things that kill you more effective at doing it. Maybe it's semantic, but your right stress can amplify and accelerate the diseases of aging. You grew up in New York, right? If I recall, you grew up in Brooklyn or in Brooklyn. I remember reading that after college, you actually went straight off to Kenya first,

is that right? What prompted that? Well, I was one of those. I've sort of spent my career oscillating between being a lab neuroscientist, studying the effects of cortisol on the brain, punch line to decades of work, is you don't want to have a whole lot of it marinating inside your head. But also for more than 30 years, I've alternated spending my summers studying a population of wild baboons in a national park in East Africa. And it's the same animals I go back to each year. These are animals I can dart to nest the tithes, get blood, do whole workups on them.

And essentially asking among them, what does your social rank have to do with patterns of stress related disease? What does your personality, what does your patterns rank have to do with patterns of stress related disease? What does your personality, what does your patterns of social affiliation? So it's been sort of a counterbalance to the lab where, you know, we've been sticking artificial genes into neurons and fairly reductive stuff like that. So I was actually about eight years old when I decided I wanted to be a primatologist. So I was kind of planning on that for a long time and lucked out. I spent all of college brown, those in the right person who shipped me off to a field site

right after graduation and I wound up sort of inheriting that site. And those have been my my baboons ever since. Did you spend the whole time in Kenya? I remember reading that you also were in Uganda and obviously there I think if my geography's correct their neighbors so that's a pretty easy switch. Where do the actual baboons like what is their scope of their residents? How broadly? Oh, there's spread actually all over Africa.

They're one of the most ubiquitous primates for a lot of the same reasons that we are, which is they'll eat anything They're carnivores, but they're also perv or they're omnivores. They scavenge dead stuff. They eat insects They'll they'll eat most anything so they can fill a lot of niches So they're scattered everywhere, but my main work over the years has been this one troop in the Serengeti in Southwest Kenya, you know, for about 25 years. I camped under the same tree, so it's really, it's been continuity with the same population of animals. What is their natural predator besides man?

Leopards, lions, hyenas. Nonetheless, if you were male baboon, the most likely thing to kill you violently is another male. Yeah, exactly. Sort of like humans. Yes indeed. Did you say it's every summer or every other summer? Well, it was initially for about 25 straight summers and then parenthood and all those complications came in. So wound up being every other, and then our kids were old enough to go with us one summer. But unfortunately, the field worked ended about eight years ago. So why is that? My Kenyan field assistant of 30 years, we started together when we were 20. He died of AIDS, political issues there, some game park issues that made it harder and harder to get

researched on. And that middle-aged realization, that I could find some new game park or new country or something and start all over, but it was kind of time to pack it in instead. So after you did your PhD, which you did in New York, right? Yeah. Rockefeller University. Did you come straight out to Stanford for a postdoc or? Postdoc to the Sock Institute at San Diego, spent a couple of years there with people

are sort of familiar with the hypothalamic hormone that runs the stress response, a hormone CRH, CRF, corticotropin, releasing hormone. I went and postdoc to this guy, Wiley Vale, who had discovered it in like two years before. So that was a pretty exciting time to be there. So I spent a couple of years there. Stanford hired me. And I've been there for 31 years. That's kind of amazing. I keep coming back to people at Stanford that you know, would have been there when I was there in medical school, but if it wasn't in the medical school, like you just weren't paying as close

attention. I honestly don't recall if you ever gave us a lecture in med school. Do you remember giving lectures in med school 20 plus years ago? I did, almost certainly, the students were paying as little attention as I was. That's true, because that was about to say. It certainly seems like something we should have been learning in medical school, And yet I feel ashamed to say, I don't know if I recall it. It was not much of an emphasis and was sort of snuck in embarrassably. Like a lunchtime seminar or something. Yeah, exactly. So that thrived them with free food. That's an even still only about five people would stay past the cookies. That's a much bigger issue we can come to.

So so you wrote a book. Gosh, how many years ago was why Zebra's don't get ulcers? That's that 20 years ago. Let's see. First edition was 94. It's gone through three editions. Now most recent one was 2004. So at some point I got to do another one.

As we talk about that and you've written a book more recently that I want to talk about as well, let's back up and explain something you touched on a second ago, which is sort of the physiology of a stress response. So walk us through the relationship between the hypothalamus, the pituitary, and the adrenal glands. So when we're under stress levels of 11-D different hormones change in our body. Most of them are relatively minor players. The two workhorses overwhelmingly first one famously adrenaline, a British term, epinephrine, sort of the North American term, output from the sympathetic nervous

system. It's on the scene in your bloodstream within one, two seconds or so after all hell breaks loose. And I just want to explain what sympathetic means to the listener. We've had this discussion before. It's not to say it's a nervous system that is kind. It just means it's one of the two branches of these so-called autonomic or immediate, not under your conscious control, right? So the fight or flight. Exactly. And the other half being parasympathetic, sympathetic fight or flight, all hell breaking loose alarms going off parasympathetic, calm, vegetative function. So not only do you turn on the sympathetic during stress, you very emphatically turn off the parasympathetic. Second main workhorse, which is already been alluded to, the steroid hormone,

class of hormones called glucocorticoids, human version, cortisol, also known as hydrochlorozoan, rat version, corticosterone, synthetic versions, prednisone, dexamethasone and such. These come out of the adrenal glands, your brain, note something stressful is happening within two seconds. Your hypothalamus is secreting that CRH, which within about 10 seconds, is getting your pituitary to release a hormone called ACTH, which within about 30 seconds has gotten to your adrenals and you are slowly starting the glucocorticoid component of your stress response. And in lots of ways, the adrenaline, the sympathetic response, the glucocorticoid response, they work on hand and hand, they synergize.

You want to metaphor adrenaline in two seconds as handing guns out of the gun locker, to whatever it's going to defend you. Glucocorticoids are building the aircraft carriers that a year from an hour are going to be essential. It does some of the slower components of the stress response, stretching out over minutes to hours. Because I was just about to ask you, and I think your question basically answers it was, why would we have evolved these two separate systems? One can only speculate on such things, but it's basically that certainly nor epinephrine

epinephrine, they stick around for such a short period of time. I mean, we don't even measure these things clinically. I can't poke your arm and measure your nor epinephrine or epinephrine level. The best I can do is collect its metabolites in your urine for evidence that it's been around. So I guess we have this hormone or pair of hormones that are on the scene in seconds, gone in seconds, and really deal with the, I guess, from an evolutionary perspective, when the tiger is there, this is what gets you to jump into the tree.

Is it doing much beyond that? And is there some evidence of chronic low levels of those hormones, which come out of a totally different part of the adrenal gland? I mean, that's the other thing that's sort of interesting is you have two separate pieces that cortex the medulla that secrete these hormones separately. And embryologically, they're two very different tissues. They start off separately. It could have just as randomly wound up that your adrenaline comes from your big toe and

glucoticoids from your thumbs, why they wound up being in the same organ? Um, is in fact somewhat just, I think, serendipitous probably because you're more likely to have your toes and fingers lopped off. And we wouldn't want to have an incidental adrenalectomy is happening. You're right. That's certainly why they didn't wind up out there in the exactly lower species is one of these considered more primitive is the epinephrine arm, something that began earlier and the cortisol

arm more recent? Yep, nonetheless, the cortical arm is just ancient. When you get stressed in your secreting glucoticoids, it's basically the exact same class of molecules, as if you were a fish or bird or reptile, nonetheless, it's very ancient wiring, and that's part of what winds up getting us in trouble. It's a system that's been serving vertebrates, doing a lot of help for them for an awful long time, and it's been a very recent modification, doing instead secrete them in response to thinking about taxes. This basic dichotomy between the very human domains where we activate the stress

response and the more typical domains of animals. So, if you and I were sitting here 10,000 years ago, I can think of lots of things that we would want an adrenaline response for, you know, the tiger jumps out of the thing, whatever. What are some of the things that would result in that cortisol response? Because, describe that it is building the aircraft carrier well, gosh, if the tiger's there, either I'm dead or I'm not, but I don't need a stress response a day from now or the next day. So what is it that cortisol was doing 10,000 years ago that was serving our interests? I want to certainly talk about what it's not doing today. When you look at what it does, it actually makes perfect sense. As long as you're being stressed like a normal mammal, running for your life, running after

a meal, where if you don't catch something, you're going to be dead by tomorrow, a short-term physical crisis. The first five seconds of doing that, which Epinephrine is critical for. That's great. If we're heading into a couple of minutes of evading a predator, being vigilant, thinking there might be, if you're getting into the realm of a couple of minutes worth of the stress response, cortisol-related glucose-quartiquant hormones are absolutely essential. So the glucose that's coming rushing out of your liver pretty important in that situation. Exactly.

So it takes you about one second to decide you're going to use your thigh muscles and run like mad. You need energy for them. And the main thing Glute corticoids are doing in the metabolic realm is collucocorticoids. They're increasing glucose levels in your bloodstream. They're going to storage sites throughout your body, or liver, your muscle, and breaking stuff that what they do is they go to the bank,

they empty out your savings accounts and turn it into cash. Glucose in the bloodstream to hand to whichever muscles are good to save your neck. What they also do makes better perfect sense with where you were running for your life, or running for a meal, which is they increase cardiovascular tone.

And epinephrine is doing the first five seconds of it by 30 seconds in glucocorticoids, you're bolstering it as well. And it's that same logic, you're running like crazy, you want to deliver that glucose to your thigh muscles as quickly as possible, you increase your heart rate, you increase your breathing rate, your blood pressure, you alter your vest

lecture so you're preferentially shunting to the exercising muscle. So that makes perfect sense also. Turns out some of the most interesting stuff glucose cordicoids do in those circumstances is basically run a triage program. They shut down everything that's not essential, not essential to surviving the next five minutes of this massive physical challenge. So digestion would be a major. Exactly. You got better things to do than digest breakfast when you're trying to avoid

mean somebody's lunch. And you're sure not going to get any metabolic benefits of digestion during this five minute. It's slow, expensive, the energy you're getting, you're getting from your liver, you're getting from your fat cells. It shuts down growth. Obvious logic there, you know, grow antlers tomorrow, if you're still around to embalm right now, shuts off reproduction. Same logic there. It shuts off all the long-term building projects

and just focuses your energies on what's immediately there. And this makes perfect sense. If you are running for your life, running after a meal, and all you need to do is look at a couple of diseases where people don't turn on the endocrine stress response, had a sins disease, shideide Raker, Syndrome, whatever. These were not diseases where somebody, who now is more at risk for adult onset diabetes

eight months for now. These were diseases where somebody goes running after their commuter bus and they dropped at from hypicalycemic shock. JFK had this, didn't JFK have Addison's? He had Addison's and that greatly constrained the famed pictures of all those Kennedy's playing touch football out.

And you know, Martha's vineyard or stuff were mostly for the benefit of the photographers. How did he survive World War II? Because he had done some pretty heroic things in that war. Although I've seen it's hard to tell if it's snarky revisionism as to how much that was public relations stuff afterward sort of orchestrated. But just to get through basic training even strikes me as an accomplishment because most people I guess who don't have a medical background wouldn't appreciate this but the tan that seemed to be eternally on JFK

is the result of the Addison's disease because the hormone you alluded to earlier that is released by the pituitary ACTH in someone who's not making cortisol is going to be very, very high. And ACTH stimulates the pigment producing cells in the skin, and that's what would give someone with Addison's Digi's darker skin. The fascinating thing with Kennedy is if it were this situation now, presumably his doctors would be on the air somewhere 24-7. There's remarkably little known about when his onset was, what the course of it was, how

severe it was. It's not quite clear, but what little is known is it had a hell of an impact on his functioning. You really do need a hormone if you, like, glucorticoids, if you were gonna be physically activated in a moment of crisis. This is sort of the amazing thing with hormones like insulin and cortisol.

I'm always impressed by how tight the u-shape is on those curves. Thyroid hormone would be another example. Certainly less so with something like testosterone. You have just a much wider range that you can function in, and the benefit is largely monotonically increasing. Sometimes if my patients will tolerate me going on and on about this, I love to draw the pictures of which of these hormones can you, you know, but to me, cortisol probably, if you thought of it as a drug,

it has the narrowest therapeutic index. To your point, too much of it will kill you eventually and make you miserable as hell on the way, and too little of it will kill you quite quickly. And what's most interesting about it is, okay, so there's an optimal level, among other ways of translating that, That means we don't hate stress. We hate the wrong amount of stress. When it's the right amount, we love it. We pay money to be stressed to get on a roller coaster, to go to a scary movie, when it's the right amount, when it's the optimal amount, we call it stimulation.

Okay, so exactly as you say, it's a narrow range. So that's a tough biological problem understanding a hormonal system that's pretty damn essential and wear an awful lot of the time you're walking on an eye Fidge where either side is bad news too much or too little But when it comes to glucoric oids and what counts as good stress and stimulation corticoids and what counts as good stress and stimulation, there's the added factor that there's incredible individual variation as to what counts as the optimal level in between. And one person's like hair raising, autobahn, society, walk one Saturday morning looking for birds while the other person goes and signs up to be a mercenary in Yemen, because that's

when they feel alive and awake and all of that, not only that it's a narrow range, but we differ so much as to what each person's optimum is. Now, I want to make sure I understand that point, Robert. And this is probably overly simplistic, so feel free to correct this. One of it would be the external scenario that is being perceived. And I can see definitely how two people can have vastly different views on that. I mean, it's the reason someone can voluntarily go and be a Navy seal and someone can say, I feel much better not doing that, right?

There's clearly a different appetite and or capacity for distress. Is that what you're referring to? Or are you also referring to you and I could be sitting here and have different levels of physiologic benefit and harm at the same level of cortisol? Both. Nice. Absolutely.

So I mean, the former, I think most people would acknowledge, the latter is pretty new, right? I mean, I shouldn't say pretty new. That's not intuitive to me. Because there's centuries of endocrinology saying, what's the most important thing about hormones? How much of the stuff there is in your bloodstream? What the levels are, and if you and I are sitting here with the same circulating levels

of whatever, centuries of dogma was, that will translate into the same biological effects. And then, I don't know, sort of endocrine revolution of 70s, 80s or so, turns out how loud someone is yelling at you, counts what the hormone levels are, how sensitively you can hear them, the levels of your receptors. In target cells, turn out to be essential as well. And there's all sorts of endocrine domains where in fact, scrui receptor levels are much more consequential and impactful than our scrui levels of the hormone itself. And individual differences in levels of receptors, what version you have, how well it works, how avatally it holds on to the

hormone, what it is then coupled with afterward downstream inside the cell. That whole world turns out to be as central to understanding individual differences as are the levels of hormones themselves. And as sensitive to all those things ranging from genes to prenatal environment to early development to psychological factors and so on. So yeah, that's a huge piece of the story now. When I hear you say it like that, Robert, it seems pretty obvious because we would talk about insulin in exactly that way. You could have two people with the exact single level of insulin, completely different physiologic response because of

insulin sensitivity. When insulin hits its receptor, it leads to the phosphorylation of AKT, and that's what leads to the Glute-4-Transporter coming up to the surface, and different people with the same insulin can do that totally differently, and different people will have a different insulin response to the same food, the same meal. That's the reason we do glucose tolerance tests. So you could basically say, someone is cortisol sensitive and cortisol resistant to make the analogy to insulin. At the end product end, absolutely. If you're an obsessive with cortisol stuff, in the 80s, there was briefly this deep puzzle in that it turned out new world monkeys,

monkeys in South America, marmosets, tamarins or whatever, when you compare them to traditional old world monkeys, the Asian and the African ones, turns out they have like an order of magnitude higher glucocorticoid levels. Oh my god, that's crazy what's that about, all sorts of theorizing about how for some reason it's more stressful to be a new world primate than an old world which didn't make a whole lot of sense. And then there was this issue of these animals should have been falling out of trees from there, their cushing's disease. And finally, somebody found an explanation.

No, somewhere back when there was a mutation in the gene for the glucocorticoid receptor in new world primates and it has roughly one-tenth the sensitivity. So the system just equilibrated out at a different set point, but that's such a great example of just natural variation, not only in how loudly you speak hormone, but how effectively your cells listen to hormone. Do you have a sense in the human population today? I mean, a log-fold difference that you just described sounds extreme. But do you have a sense of what the variability is in humans today? Is it a two-fold, three-fold delta on the receptor side?

Gut feeling and reflecting the fact that my world, the brain, you don't get to measure receptor levels anywhere near as easily as in a white blood cell, well under an order of magnitude. We just acknowledged, or you just pointed out, that when a zebra sees a lion, everything that happens as far as the fast end, what I would call the acute and the subacute stress response, is perfectly evolutionarily sound and completely in the best interest of that zebra. We could also come up with a countless examples of 10,000 years ago, or even today, when the same thing is true in humans.

When did that transition occur in our species to where you started to see either something in the civilization or society that was unhealthy? So today, I could point to a thousand examples, social media, you name it. I mean, it's an infinite number. When did that start to crop up? What does your research suggest is the arrival of that? I think it predated us being humans. And instead is a feature of smart social mammals. Because you see indices of stress-related stuff,

bad wounds, that's what I've spent my whole career on, and other non-human primates, cetaceans, elephants, and such. Okay, so why study bad wounds if you're trying to understand human stress? And it turns out they perfectly illustrate the point you just brought up. If you're a baboon living in the Serengeti in East Africa, your life is pretty good. It's a fantastic ecosystem.

Baboons, they live in these big troops, 5,200 animals or so, so they really don't have to worry about lions very often. The infant mortality rate is lower than among the neighboring maceye tribes people, and probably most importantly, unless it's a once-generation drought. If you're just a bad wound going about your everyday business, it takes you about three hours a day to get your days calories. And that has a critical implication, which is if you only need to spend three hours of sunlight each day, getting enough food to get by, you've got nine hours of free time every day to devote to being miserable to some other baboon. And that's the key thing.

They are well off enough in our westernized sense that they consider around and generate psychological stress for each other. Overwhelmingly, if you're a baboon in the Serengeti and you're miserable, it's because another baboon has worked very hard to bring that state about. They're wonderful models for westernized disease. In that very few of us get hypertensive because tigers are chasing us. Instead, it's psychosocial stuff that we invent and that we can wallow in for hours every day.

And that's exactly what bagoons do through great models for Westernized stress. Do we have evidence, I'm not sure it exists, but in the humans, I would just be willing to bet that if you and I were subjected to the same external stressor, I would just be willing to bet that if you and I were subjected to the same external stressor, I would probably internalize it more than you. That's my guess. So if we were both baboons and there was a third baboon tormenting us, is it safe to say that you could be the baboon that would roll with it more than me? Individual differences like that, absolutely. My guess is both of us would respond to it by saying, I'm just going to get a longer, a longer CV and then you just got to regret it someday, pushing me around. They'll be sorry when they see how many

degrees I have. But yeah, individual differences. One of the things that I focused on, you know, I spent my first 10 years deciding rank and status, social status, everything. If you're a baboon and you got a choice in the matter, you want to be high ranking because on the average, you have lower glucorticoid levels, you're resting blood pressures, lower, all sorts of stuff works better. But what took me some growing up out there to do was to realize that yeah, social rank is important. Far more important is the contextual meaning of your rank. Is that the same as your perception of your rank, or is there there's more to it, right? Well, it's what the rank means in your particular troop.

You can be a low ranking guy in one of two different troops and one troop simply because of its culture. And that's a perfectly scientific world word to use for another species these days. In one troop being low ranking could be a whole lot crappier than in another troop in terms of how often somebody in a bad mood displaces aggression on you in terms of how often somebody actually grooms you and off in terms of how often you get to finish a meal before somebody steals it from you kind of thing. So the same exact rank means different things in different sort of baboon cultures. So I'll take an extreme example. In a prison, there's a clear hierarchy starting with the warden, the guards, the inmates, and of course within the inmates, there's

a hierarchy, presumably I'm making this up, but certainly the pedophiles the guards, the inmates. And of course within the inmates, there's a hierarchy, presuming I'm making this up, but certainly the pedophiles would be at the bottom of that list and a violent criminal would probably be at the top of that list. So within that hierarchy, there's probably a manner in which you would be perceived as a function of that unique environment,

which is so artificial in its own way, but that wouldn't necessarily be the same outside. Absolutely. And one of the most interesting things about us, us humans, when we talk about what across all sorts of primates being low ranking in general is bad for your health or what about humans we don't have ranking in the same system that sort of other primates do in a strict linear kind of way. But the other thing about us is we belong to multiple

hierarchies at once, and we can have very different ranks in them. So for example, family work sports team. It's happy. You've got some guy who's the mail room clerk in this giant corporation and you could not possibly be lower status, but he's the captain of the company softball team this year. And you better bet when you ask him what's important in his life, nine to five Monday to Friday is just a stupid way to pay the rent and what really matters is when the weekend comes around, you have somebody with a horrible,

low status job who's the deacon of their church. We belong to multiple hierarchies and we are very good psychologically at deciding that whichever hierarchy we're highest in, that's the one we define ourselves by. Let's take another extreme example, which is you take people who are very successful in what they do, you know, whatever they're the most famous hedge fund manager or an entrepreneur that started some great company, you would argue. Well, they seem to be pretty good on the food chain, but yet many of them would say or you could measure objectively their hypercordosolemia is problematic. So it seems like there's even more than just that ranking, right? Isn't there something else? Because they're at the top, if they were baboons, they're the alpha, but they're still grossly stressed out.

In other words, thank God we're more subtle than baboons, but it turns out baboons are even more subtle than just rank. They have personality. And you can be a high-ranking baboon, and personality differences. And again, this is a scientific word as this culture. If you're a high-ranking baboon, and you're worst rival sneezing a hundred yards away, as seen as a major provocation, you're going to have much higher, good, corticoid levels, than if you're a highest ranking baboon for whom that's no big deal. And in fact, often,

you may have higher glucoticoid cortisol levels than if you're number 10 or number 20 on the hierarchy. There's lots of psychological filter stuff. And I spent a ton of time studying that baboons differ as to how readily they see things as being provocative or not, threatening or not. You're sitting there and again, your worst rival shows up and takes a nap 100 yards away. There can be two baboons of the same rank and one of them keeps doing exactly what he's

doing. And the other one is interrupted from whatever nice social thing is happening. He's agitated and he's doing. And the other one is interrupted from whatever nice social thing is happening. These agitated, these vigilantes got to look at the guy and lunge towards him a couple of times. If we're going back, if you're worst rival taking a nap is as disruptive as the guy threatening you in your face, you average about twice the cortisol levels in your bloodstream after controlling for rank as a guy who can tell the difference between the big thing and the little thing. Maybe this is too deep a question and the answer isn't known, but what is it that actually transmits that information through the filter of your personality into the physiology that's very well understood. So I understand the book ends, right? I understand how the visual cortex takes the guy who's your enemy sleeping over there and transmits that to your cortex.

And then I understand how the sympathetic chain kicks off the response. Is there a link in between those the processing link? Here's one of those filters. You take people and you're flashing up faces at them, stick them in a brain scanner, and you're looking at how jumpy their amygdala is. Their amygdala central to fear, anxiety, aggression, and such. And what you see is tremendous individual differences in you show somebody a face with kind of a neutral expression, does this person look happy, sad, angry, threatening, whatever, and lots of variability. And you look at the people who tend to view neutral expressions as threatening. In other words, they see threats that most other people don't. What is that correlate with a bigger amygdala? Physically larger amygdala.

A physically larger amygdala amygdala with a higher metabolic rate and amygdala that is more electrophysiologically reactive than stuff. Let's back up for a moment. I mean, tell people in case they don't know where the amygdala sits, what part of the brain it evolved from and why it's sort of referred to as this reptilian brain. I think everybody's heard of the amyg evolved from and why it's sort of referred to as this reptilian brain. I think everybody's heard of the amygdala, but I think you could explain this in a more interesting and accurate way.

Okay. Amygdala is like one of the anchors of what's called the limbic system in the brain. Limbic system, it's the part of the brain that's all about emotion. Not surprisingly, mammals have a whole lot more limbic development than fish do. Fish are not famous for their emotional lives. Limpic systems, arousal, fear, anger, lust, love, maternal, pair bonding, mother, infant bonding,

all of that, and it's a whole series of structures. Not surprisingly, ancient in mammals, infant bonding, all of that. And it's a whole series of structures, not surprisingly, ancient in mammals, not surprisingly, highly complex interconnected, not surprisingly sitting underneath the cortex, the cortex that more recently evolved part of the brain that does your taxes, all of that limbic system underneath there, all this subterranean emotion stuff. And a migdala is one of the key limbic structures and it's involved in fear. It's involved in anxiety, it's involved in aggression. You learn to be afraid of something or somebody that didn't use to scare you. And you're

remigdled as the exact same sort of cellular basis of learning that goes on another part of your brain when you learn somebody's middle name and actually remember it. Your amygdala learns to be afraid of new things. And when you manage to stop being afraid of something, when you stop being afraid of thems because it turns out, oh, they're actually more similar to use than you thought there are some say, it's your amygdala that becomes less reactive to stimuli like that. So your amygdala is absolutely central to some of our worst human moments.

It's so interesting because it's sandwiched between, you know, you can think of the human brain as having sort of very grossly three parts, right? This brain stem, this mid brain, which the amygdala, you could argue, is the mayor, and then the cortex that you describe, it's not an oversimplification, I think, to say that as the complexity of the organism evolved, so too, did that hierarchy, right? I mean, the brain stem basically handles everything we don't have to think about ever, breathing, and all of those autonomic, and sympathetic parasympathetic functions. And then you layer on this midbrain that does everything that you said, which is still kind of happening beneath consciousness.

And then of course, there's where most of us live in our cortex where we think we live, which is we're thinking these thoughts, but it seems we're maybe not as aware of how influenced the cortex is by what lies beneath it. Exactly. Which is incredibly important. If you think of this kind of ancient reptilian brainstem part of the brain, what does it do? It keeps track. It makes you breathe every now and then without having to think about a boring sort of stuff,

then on top of the emotional limbic system, then on top of that cerebral thinking, cognitive cortex thing. It's very easy to come up with a conceptualization that what's fancy about humans is, for example, you're a lizard, and the only thing that's going to change the functioning of that ancient brainstem stuff is if you're bleeding, if you're too hot, if you're too cold, just like boring physiological states, once you layer a mammalian emotional limbic system on top, suddenly you can do something no visitor on earth can do. You're sitting there and you're some will to beast and some other scary will to be shows up and

is peeing on some tree in your territory and nothing regulatory has changed in your body, but your heart starts beating faster. Aha, your emotional brain can alter sort of the basic regulatory stuff down on the basement. Now you go one step higher and you lay where a cortex on top of it, and now you could do amazing stuff. You sit there and you think about the fact that your heart's going to stop beating someday. And you start breathing faster. And your brains, then the more ancient stuff has altered as a result. And you've just done something not only that no reptile can do, you've just done something that no warthog can do, which is think, think about something that's scary or arousing or remember the time that you would, and suddenly something changes down below there.

So there's this easy picture of sort of top down complexity once you get to us and where the cortex can regulate your emotional brain and that regulatory brain at the bottom, your emotional limbic brain can regulate what's far more interesting or underappreciated. This is exactly what you bring up, which is those lower levels can influence what's going on up above. One example of this, this is like this classic, great study and sort of physiological psychology, social psych. You take people, and I think in the study, they would take male volunteers, heterosexual male volunteers, and of course they were no doubt college freshmen taking psych 101. And

they had these guys walk across this really scary suspended bridge. And the deal was that either halfway across the bridge, you were met by from the other side of researcher who happened to be an attractive female. And she would ask the volunteer some questions, and what do you think of this bridge, or how is it walking across this, or whatever, the other half of the time you would not encounter this person until you were safely out of the other end.

Then they would ask you to evaluate the attractiveness of the person. Same person. That same person. Seeing her in the middle of the bridge or at the far end. Exactly. Say, hey, remember while you were doing that, there was this, you know, do you want to rate her attractiveness? Was she friendly?

Did she seem smart? And what you would see is guys in the middle of the bridge with their hearts racing because they're terrified would do some misinterpretation. Why is my heart beating so much faster than if I was standing safely? So they would rate her more attractively in the middle of the bridge? Exactly. And then the ceiling of detail is now you do the same experiment, and you give the person a beta blocker so that they don't have the accelerate, and they don't rate the person

as attractive. Is it the same with the beta blocker? You would treat you. You do nothing to their ratings of them as how smart they seem, how kind they seem, whatever it's just this, okay, if my heart's racing it must be because so that's a great example boring reptilian regulatory stuff down there is helping influence what do you think your emotions are that reminds me of the 1995-ish movie speed with Kiano Reaves and I'm blanking our name. Bullock.

That's right, center Bullock. Yep. We're at the end of that movie. There's some cheesy line about how relationships that start under this much distress, you know, it's dangerous. But, but of course, the other read on that now is, yeah, if you're on a bus that's about to blow up, like, I think you're going to think the chair is attractive, right? Potentially.

Yes. Wow. I have a photo that moved me in years. Thanks. I'm sorry. That was so. You can go home and I'm sure Netflix will stream that for a while. Right. So I've read something you wrote. I can't remember where it might have been in another interview

that, and I didn't know this. And this is a great example of why I just love doing this podcast because there's never an exception to how much I'm learning. It's like drinking from a fire hose. And you'd think I would have remembered this from medical school. The neuron of a human and the neuron of some other organism, when you look at it at the single cell level, can't really differentiate it. If I showed you two microsubsides and here's a human and here's a fish, huh? So what is it about and this is maybe getting us a little off topic, but I also think it feeds into this broader Issue of like the stew and the alchemy of how this stuff is put together But if we all have the same neurons what is is it the number of our neurons like what is it that enables us to have? All of this additional torture? Yeah, it's incredibly interesting because I mean, there's there's three and a half people

on earth who have spent their entire careers being able to tell the difference between like a tree-shroom neuron and a human neuron and could recognize it and their sleep. But yeah, for the most part, we are not humans because we have invented brain areas that you don't find in other mammals, or because we've invented neurotransmitters that you don't find in other vertebrates, or types of neurons. Here's a couple of types of neurons that people use to think we're specific to humans, and it turns out you find them in elephants, and whales, also, and that's plenty interesting. But it's the same enzymes. It's the same gene regulation.

It's the same, you know, we're sharing 98% of our DNA with a chimp or a binobo. So you say we're going to humanists come from. And I think it's exactly the issue you talk about. We have the same signal, transduction pathways and neurons, as you see in a fruit fly. And what's the key difference? Isn't that a bit humbling when we just think we're that special? And it's the where you can take one of their genes or one of our genes and stick it in the other one and it functions just fine.

Or you could take it from a single cell organism, some genes related to program cell death, you can do that. So what's the big difference for every neuron that a fruit fly has, we have a hundred million. And sort of the sound bite that I think summarizes all of that is with enough quantity you invent quality. And this is this whole world of emergent properties of complex systems. You take one ant and you put it on a table and nothing that it does makes a huge amount of sense. And you put 10 ants there and pretty much the same thing and you put on, I know, a thousand and maybe they start making a trail or something. And you put 10,000 and they build a colony, and they farm mushrooms, and they take aphids as slaves, and they could keep the temperature in the colony, plus or minus

two degrees, and they have specialization of labor. And no ant has any more rules than he had when he was watering around on the table by himself. And you put enough of them together and complex adaptive stuff emerges out of the very simple rules that each of those components has for dealing with another component. It almost defies entropy, doesn't it? Like, why does that happen? It's amazing that it does that. And that's what our brains are. We've got more ants that are coming together in our heads than does a fruit fly and you get more Complex emergent stuff happening. It blows my mind. So let's go back to some of this stuff Maybe about a year ago I read something that really frightened me because the implications were so significant

If a mother is under great stress There was this critical window in which her child could see something in her eyes that would communicate that stress to her or maybe it wasn't in her eyes, maybe it had been just through her entire face, but it would imprint epigenetically into the child and alter many features about them as they would age, for example, their propensity to be depressed. I mean, I remember reading this in sort of a lay press thing, so I don't even think it got into the description of epigenetics, but that was the only assumption I could make was that this must be modulated through that mechanism.

Do you see evidence of this in animals? I mean, it's absolutely. And it's one of the trendiest topics around, like, hooray science finally recognizes childhood matters. Like what your child is like has a lot to do with what sort of adult you're going to wind up being what do you know? And like lots of childhood adversity versus childhood security and, you know, very different trajectories. And what's been the huge mechanistic challenge for the field is understanding,

so what is it about being in a scary neighborhood or an unstable home or having a parent read to you? Or what is it about this whole world of developmental individual differences? What are the nuts and bolts changes that occurs in a kid? So that as an adult, they are now 30 fold more likely than the next person for this or that to happen to them. And this whole trendy field of epigenetics, which is early experience doesn't change

your genes, doesn't change your DNA sequence with some like, you know, circus trick exceptions. You've pretty much got your DNA sequence forever. What epigenetics is is early experience changing the regulation of your genes. How easily you turn certain genes on, how easily you turn others off in different parts of your body, different parts of your brain, and so on. And that's exactly the sort of domain where you see the sort of stuff that you outlined. So that, for example, if you're a fetal rat and you that rat

have made a terrible decision, you've picked the wrong room to be developing in and you happen to be inside a mother who's highly stressed. She's secreting a lot of rat glucocorticoids, which get into the circulation through the placenta and to the fetal circulation into the kid's brain. And one of the things that it does is it causes an epigenetic change in the amygdala. So is that rat going to be born with a larger amygdala or is the phenotype more complicated than just size? It size in a bunch of other things as an adult, it's going to have a bigger amygdala and it's going to be more

excitable and it's going to be more prone towards interpreting a neutral situation as a threatening one that's virtually the definition of rat anxiety disorder seeing menace that other people don't. And you see much the same evidence in humans by now. Early experience. Forget early experience. What kind of kindergarten teacher you had. This is fetal early experience. And this is exactly a domain where you get potentially a lifelong epigenetic effect. Okay, so that turns out to have a hell of an implication that's just the most exciting subfuel around there by now. Okay, so you were fetus and got exposed to lots of mom's glucocorticoid levels. And as a result, as an adult, you've gotten a large domicula, and you see threat all over the place that other rats don't.

And among other things, you secrete elevated levels of glucocorticoids, because the world is full of menace that only you are seeing. So you get pregnant, and during your pregnancy, as a result, your fetus is exposed to elevated glucocorticoid levels. And to be clear, it's not because you have altered the germline genome. It's that you have changed the expression of the gene, which has altered the phenotype, and now that phenotype is being passed generation to generation through parallel expression. Exactly. Something term non-genetic transmission of traits non-mendelian. And people have now shown some of those traits. You see that ripple. It gets smaller each generation, but it's their half a dozen generations later. And the

exact equivalent of some of these have been found in humans. In other words, individual differences are arising not only from experience, but from the multigenerational transmission of some of the consequences of experience, which is just mind-boggling that that can work that way. Let's go back a little bit to why this is problematic. So at the outset, we alluded to this idea that it's a misnomer to say stress kills. I'd love to hear if you have a particular definition of stress. I probably butcher this stuff, but I sort of think of stress as the external thing, and I think about it as it's anything that is sort of emotionally or physically either

chronically or acutely distressing. I mean, that's sort of a dumb definition because it contains the word stress, but I think people understand distress a little more than they understand stress. But of course, it's your response to that physiologic response, right? Which is so let we can quantify this stuff in terms of what hormones are happening in the body

and how the hormones are moving the body. It's your response to that that probably has a greater impact on your health. So let's go through three things. Help me understand how hypercordicellemia and or it's accompanying features will impact the brain, especially well through any timeline you want. I'm obviously interested in the aging brain, but I can't imagine this also doesn't impact the developing brain. This is basically what I've spent my whole professional career thinking about. And historically, the first place where people sort of realized something scary was happening was a brain region called the hippocampus. Hippocampus is all about

learning and memory. You want to have a hippocampus. It'socampus is all about learning and memory. You want to have a hippocampus. It's the main brain region that's damaged in Alzheimer's disease and it's vulnerable in lots of other ways. Turns out it's extremely sensitive to glucoricoids, translated more reductively. It's got extremely high levels of receptors for glucoricoids by the standard to the rest of the brain. And what's the evolutionary basis for that? Is that to have a feedback loop?

There's two reasons. One is to have a feedback loop, but the other is, okay, so the hippocampus remember stuff for you. You don't remember everything. You don't remember where you were on 9, 10 as opposed to 9, 11 kind of thing. Your memory processes has to come with a filter saying, is this one important? So you're saying the cortisol amplifies memory consolidation and that you use this to consolidate stressful memories as a way of learning. Exactly. Along with epinephrine and neuroepinephrine indirectly, they have some of the same effects. So cortisol crosses the blood brain barrier with no difficulty? Exactly.

I assume epi and norepi do the same. They have to work more indirectly heavily through the vagal nerve because they don't get them as readily. But some of it is also neuroepi being released within the brain during stress. So it has some of its own memory enhancing effects. Again, a great example of evolution's got this awesome system set up and it only gets out of whack when the stimulus becomes too much. You do want that imprint, but you don't want that happening full time.

Or stated another way, this is the reason why you don't get much out of a class if you're semi-comatose and you had two hours of sleep last night. If you're like three-coordinate, your glucororoid levels are low, you're semi-comatose and you have two hours of sleep last night, you're, if you're like three-coordinate, your glucoricoid levels are low, you're not consolidating stuff. If you are out of your mind terrified because there's a lion sitting next to you, you're not going to absorb much either. Inverse, you optimal range, all of that. So it turns out the optimal amount of glucocorticoids, something that is moderately stressful, in other words, something stimulating, does great stuff to your hippocampus.

It increases blood delivery there, glucose, oxygen, it makes the synapses, the connections between neurons more excitable in the hippocampus. Does great stuff, a little bit of arousal alertness is a good thing for learning and memory. Now instead, transition to your stressed 24-7 ever since you were like 10 years old kind of thing, and you're in the range where glucose quarts do exactly the opposite. They decrease oxygen and glucose delivery to the hippocampus. They make neurons less excitable. They disconnect synapses. They cause the processes in neurons to shrivel. They block the birth of new neurons there. They make other insults more damaging to neurons in the hippocampus. What do you

have there? That's the world in which, if you were stressed out of your mind, memory doesn't work so hot. And what we're increasingly realizing is, if you're exposed to excessive glucoticoid levels, like on the scale of years to decades, you're going to make this part of the brain get older faster. Which speaks to something that I know you're quite passionate about, which is the differences in how socioeconomic status can sort of affect generational changes in this manner because you know, use the example of a 10 year old. Well, I did my residency in Baltimore. Let me tell you a 10 year old in inner city Baltimore

who's in the wrong house versus a 10 year old in Palo Alto who's in quote unquote the right house. And look, that's not to say that you could have a 10 year old in Baltimore that's got a great environment and 10 year old in Palo Alto, who's in quote unquote, the right house. And look, that's not to say that you could have a 10 year old in Baltimore that's got a great environment in 10 year old in Palo Alto that's dealing with a whole bunch of other different issues, which, you know, especially in the air of social media. But all things considered, probably, realistically, that 10 year old in Baltimore is going to have a much harder time given what you just said. Or I don't know if stated the other way.

I have a friend who's a cardiologist who splits his time between a hospital in Oakland and a private practice in San Francisco. Some of the time what he's doing is dealing with eight-year-olds who are considering getting a pacemaker because the ski season is coming and they are wondering if they're going to be in shape and time for that and maybe and then back in Oakland he's dealing with 50-year-old elderly men who are having heart disease. Yeah, socioeconomic disparities are I won't get on my soapbox now. When you look at the source of variability and health among humans on this planet, socioeconomic differences, differences in absolute levels,

differences in degrees of inequality within cultures and within communities and so on, as an enormous predictor of health. You want to look at the most medically impacted, low-ranking primates you could find on Earth, look at poor humans. Because when humans invented socioeconomic status, and the capacity to be poor, they invented a way to subordinate the have-nots like no-chimp on earth could ever dream of doing.

As you've alluded to, there's something else to it. You know, recently I interviewed an amazing physician named Tom Katena, who practices in the new Bammoutons in the south of Sudan. He's the only physician to take care of one million people who, as you know, are being killed by their own government. Bashir is indiscriminately killing these people. My discussion with Tom was one of the most riveting discussions I've ever had with a human being. It just happened to be in front of a microphone.

But one of the things that just as an afterthought we were discussing that surprised me is we were going through all of the different things that people die of there. They don't have vaccines. You've got measles outbreaks that are killing people left right in the center and the trauma, like, you know, the shrapnel blowing people apart. Not surprisingly, they're just not getting the same chronic diseases, you know, and the cancers they get are not the cancers we get, and they're not getting heart disease, and they're, you know, almost unheard of to get type 2 diabetes. But what really surprised me is there was no suicide. And I found that

as the single most interesting thing I, yes, I learned from Tom, which was, we would look at their life and think, that is an abysmal existence that I couldn't tolerate for one second. And yet, I would have to guess that their level of cortisol might be lower than ours, even though they're in a much worse environment. So whether it's that sense of community that they have or the shared purpose, there's something about it. So in other words, my point is, even in the presence of such great poverty, it seems that there's ways that this can be overcome, whether it's through there's no comparison to anybody else because another point he made was most of the folks there don't even know they're in Africa. Like they don't necessarily know that

Africa is the continent in which their country resides. So is the bigger issue there, you think that there's no disparity. So even though that's complete poverty, there's no real perceived disparity. Or do you think it's the sense of community? Like what would you hypothesize explains that health, that mental health? All the above. There's a whole world of people who study happiness, along with more traditional public health people who study things like longevity. You look at the quarter poorest places on earth and indeed people there don't live very long and are miserable. But once you get past sort of the subsistence level, there's not a great relationship between the wealth of a country, GDP per capita, anything, and levels of happiness or life expectancy. And you look at the fact that you as a shorter life expectancy than Cuba and Lebanon and Costa Rica, and it's

like the shame of this country kind of thing. Once you get past mere subsistence level, income is not a great predictor of any of this stuff. And that's instead where you get into worlds of social capital and social support. And when you look at the whole literature, and you look basically at every westernized country under earth and it's now seen as they become westernized. And what you see is the health socioeconomic gradient. The poorer you are, the worse your health on the average. The more of a whole array of diseases, you get, not all of them, but a huge number.

The more impactful they are. And when you look in the West, the United States is the poster child for that. We've got the steepest curve of any country on earth. the more impactful they are. And when you look in the West, the United States is the poster child for that. We've got the steepest curve in any country on earth. And the westernized world, the least steep ones are you bet. Of course, the Scandinavian countries, ever reliable, sort of utopias. And then you begin to unpack why this relationship occurs. And like some incredibly smart people have spent their careers looking at it most obvious one is If you're not healthy, it's very hard to pull off being the CEO of a company poor health precedes and gives rise to poor socio-economic status

Okay, that's plausible that turns out to explain a tiny percentage of the variability and you could look at the status socioeconomic status of the home in which a child is raised and that to predict or they're likely that of diabetes half a century later. So absolutely the socioeconomic status comes first and explaining the vast percentage of the variability. Okay, so next thing maybe it's just that well everybody's kind of the variability. Okay, so next thing, maybe it's just that, well, everybody's kind of equally healthy. It's just that the really poor people are very unhealthy. We have a step function.

No, you start with Jeff Bezos and Bill Gates and every step down there and statistically, the lower you go down every wrong of the way, the poorer you are. The poorer you are with respect to alcohol. I'm sorry. The poor your health. Yes, yes, thanks.

So now you unpack that and what's the most obvious explanation? And this is what people call a neomaterialist explanation, which is obvious. The poor you are, you don't have healthcare access. You don't have health insurance. You can't go to the doctor as readily. Your care is more lousy. That's obviously that explains everything that explains virtually none of the variability in the data because

you see the gradient nonetheless in countries with socialized medicine, universal healthcare, you see it for diseases where it doesn't matter how often you get healthcare access, juvenile diabetes. So it shows an SES gradient kind of thing. So it's not healthcare access. You then look cross culturally and you see wildly different income levels and wildly different levels of healthcare access. And you see very similar life spans across these countries and very similar gradients. So what people spent like the last 30 years doing is having this huge shift towards it's got so little to do with the material aspects of wealth or poverty. It's got to do with the psychological aspects.

It's got to do with the stress. First key finding, somebody at UCSF named Nancy Adler who's done wonderful research showing, okay, your socioeconomic status, your wealth, your objective measure of wealth, is indeed a predictor of your health. Turns out, at least as good of a predictor is your subjective socioeconomic status. On the level when you look at people around you, how do you, how are you doing compared to other people? Where would you place yourself on this 10 step ladder in terms of what's your absolute SES? What's your subjective one and by asking

it that way? You're asking the person to consider the community that's most pertinent to them. Who's the comparison group? My next-door neighbors, Warren Buffett, in-between, whatever. When you think of other people, how are you doing compared to them? And it turns out your subjective SES is at least as good of a predictor of your health as is your objective. In other words, if you took someone's income, which is quite objective, it would offer no more prediction than asking that person in the new but mountains. Where do you rack up in this tribe? And it's sort of like, you know, sort of top two thirds. Yeah, exactly. Or another way of stating that is you look in some

bloated corporation, and there's some guy who's the assistant manager, the mail room, and that's an incredibly status-filled position for that guy. And there's some other guy who's number two in the company who was just passed over to be number one, and the only pertinent thing in his mind is not the 99,000 employees that he's higher ranking in, that there's still somebody ahead of me. And you would see the same thing in baboons. In other words, it's not being poor, it's feeling poor. The next critical piece in the story is work from this guy, Richard Wilkinson in the UK, who shows what's the best,

most like effective way to make somebody feel poor, independent of their absolute levels of income, surround them by inequality, surround them by reminders of all the people who are doing better than them. I mean, this is where social media, it's the amplifier to all amplifiers of this, right? You can't go 10 minutes if you're on it without looking at somebody who's obviously better looking, obviously smarter, obviously richer, obviously having more fun.

I think this has been pretty well documented, right? Life style of the rich and famous, or you could be driving down a freeway and somebody passes you in, I don't know what counts as a high status car these days, the cost of fortune, but they come speeding past you and you can feel crappy and diminished and like a less successful human. And you never even saw that person's face. This is unheard of in the history of humans or a primate of being able to feel socially subordinated. And you don't even interact with the person. Oh, there's people out there with, you know, at least if the next door neighbor has more camels

than you, that's a very like tangible, real thing in terms of like likelihood of surviving that extra, income inequality explains the mediating effect between objective socioeconomic status, subjective socioeconomic status, and health outcome. What I'm hearing you also say, though, that's a more subtle spin on this, is it's not necessarily global income inequality,

it's local income inequality, that is much bigger. But what technology is allowed us to do is to like what counts as low. It makes the local counts as low. That's right, that's exactly right. It's expanded what local means. You can sit there and watch, I don't know, lifestyles are the rich and famous. And back when you would never have gotten into like the petty or fiftoms, castle or what. And now you can see all the crap they

have that you're never going to get and feel less loved as a result. It's so interesting to hear you talk about this. This is a topic that I think anybody listening to this is well aware of, especially if you're a parent, because you also have to think about this through a developmental lens, which is at least when you and I grew up, I didn't grow up with a lot, but you really had no idea what was different, right? Like you simply, everybody was the same. I mean, everybody's parents bought used cars, and instead of new cars, and everybody had more or less the same sort of clothing that wasn't exactly the best and whatever.

So at least you could argue, well, were we at least spared some of this difficulty during a critical window of development. And what happens now to a 10-year-old that's got a smartphone and is subjected to this, because I remember that funny show, Lifestyles of the Rich and Famous. I can still sort of hear the goofy cheesy theme song. I think I even probably watched it once or twice as a kid. But it's a lot easier when that's the one exposure you have to extreme wealth or disparity, and either you can watch it for one hour or not, but it's quite a different thing if not to pick on the Kardashians. I'm just, but if you're inundated with, oh my god,

look at how awesome the Kardashians are and what they're doing and how great their life is and multiply that by three log orders. Do we have any data that suggests that we are at a critical juncture? Because now I was having a discussion with a friend yesterday, which is, is there evidence of any greater transition in technology in both a positive and negative way than this generation to the last. Is this truly the greatest step forward? I would assume so, but the things we worry about, people have been worrying about for centuries. Oh, my kids, they don't go outside, they don't play,

they don't have like meaningful relationships because they spend all their time talking on the telephone. They spend all their time listening to their transistor radio. So maybe we're blowing this up. Maybe this is just this generation's version. I mean, I guess the one difference is when you're talking on the telephone, when you're listening to the transistor radio,

I don't know if it creates that global to local phenomenon quite as easily or as quickly or with less resistance as we see. Maybe you're right. Maybe this has always been one generation's struggle with the last. But what you get is an amplifier now, because if you're an insecure, socially isolated, periatal, lessened kid who's vulnerable in all sorts of ways. And, you know, no matter what decade or century it was, you're the last one picked for the

game, you're the one who released popular or whatever, and that has all its corrosive effects. Now if you really set your mind to it and you're that kid, you could spend 24, 7, just wallowing toxically in evidence of a gazillion other people who are better looking than you and more popular and invited to parties. You'll never be in for it amplifies further. And the technology does absolutely that. What I think it does is it makes the vulnerable more damaged than in the past. I think it's safe to say these amplifiers aren't going anywhere. So rather than wallow in their harm, I guess the more relevant question is, what do we do if you're a parent today, or not a parent today, and you're thinking about this through the lens of yourself

versus your kids, whatever, what are the steps that one can take to become less susceptible to these forces that seem to drive this? Because I want to take a step back for a moment. When I think about these areas that we've talked about before about the impact of nutrition and sleep and exercise and stress or distress to make it more the term I use. When I think about this personally, the one I'm most worried about is the last one. I think I've got a pretty good handle on nutrition, and it's in many ways easier to control. I feel like I'm more in control of what I eat, And when I make bad choices, I'm usually doing them consciously. Like I've decided I'm going to eat this pizza versus I can't help myself. I'm going to eat this pizza.

Similarly with exercise, like, and again, I'm not saying this for anybody else, but this is just my personal thing. And even with sleep, like once you commit to it, which is not something I did until probably seven or eight years ago, that I sort of committed to, wow, this really matters. And to forgo this thing, bad idea. It's this last one that really drives me crazy, which of course doesn't help matters because the fact that it drives you crazy makes it worse. But I'll give you an example. As a general rule, outside of the immediate post-prandial period of a high glucose meal, far and

away my highest blood glucose is always in the morning. Now I wear a 24 hour glucose meter, kind of a weird guy. For almost four years I've been wearing a glucose monitor all the time. So it measures my glucose 24-7 at one minute increments. And out of say 365 days in a year, I'm easily wearing at 330 days of the year. So I've got a lot of data. And without a question, when you look at a 24 hour period, if you stripped away the x-axis of time, I could easily identify mourning for you without exception. I'll give you an example. This is not something I'd plan to do. I had breakfast yesterday, yesterday being Sunday, really early, because I woke up with my kids

made breakfast. I normally don't eat breakfast, but I did. So I had a breakfast 730 in the morning, did a workout, had to catch a flight, didn't have time to eat after, had a very, very busy day, didn't have time to eat after. It had a very, very busy day. Didn't eat a single thing, got to the hotel around 10, 30, or 11. Didn't want to eat, so didn't. Got up this morning. It's been almost 24 hours since a meal, and I looked at my glucose meter, and it was like, said 110 milligrams per day. I was like, there's no way that's right. Calibrated it, sure enough, it was 110. Now, there is no way that's right. Calibrated it, sure enough it was 110. Now, there is no earthly reason I should have had a glucose of 110 milligrams per deciliter, 24 hours after my last meal,

which by the way, was bacon and eggs. It's not like I was eating pancakes, right? Well, I promise you if I could spot check my cortisol, it was high. And here's the thing, before I went to bed, my glucose was quite low. You know, my glucose was probably 80 when I went to bed and it slowly rose. And sure enough, as my day wore on, today the glucose went lower, lower, lower, lower, lower.

It was about 78 before you walked in here. I'm not alone, by the way. So I've seen this a lot clinically with patients. Once you start putting these 24 hour glucose sensors on people which a lot of my patients are now doing, you get this insight into this horrible thing that's happening when we think we're sleeping and nothing else is going on,

but we're ruminating or God knows what else. And fits perfectly with morning awakening is when you get your highest glucoit-quite levels, which is probably one of the main driving forces on the increased blood glucose level. And when you think about it from a circadian standpoint, what's the most challenging thing you have to do each day in the absence of any major tumult? Get up, start functioning, all of that. It just seems like it's disproportionate.

Certainly, the dawn effect has been well-described. It's more amplified in people with type two diabetes, which is another interesting point, right? Which is, why is it that someone who already has glucose to this regulation would have an even higher cortisol response in the morning, and you'll see enormous fluctuations in glucose? I guess my point here is, this seems like a harder problem to fix,

and certainly meditation is by far the best tool I have ever found to even approximate getting this under control. But it's still hard because it's not like you have a pill. If your blood pressure is high, well, I think it's probably best to fix it in any way possible, but we also have really great drugs that fix high blood pressure that can at least mask these things. We don't have a pill to fix hypercordisolemia. It's one of the most complicated endocrine situations, and yet as you've described eloquently, it's also so innately wired into us, and we have this miserable midbrain that's just killing us.

First of all, I'd love to hear your thoughts on meditation, but then also other things that given how much time you've spent thinking about this problem, I'd love to know how you would suggest someone who doesn't have quite the zen mindset that I can tell you do. Which is someone else be thinking? Right off the bat, I'm delighted to see that I have a persona of us and I'm actually like one of the most type-based rest people you're ever going to run across. I've spent 40 years professionally studying how bad the outcome is going to be of all of these like bad lifestyle aspects without having anything insightful to say about how to actually fix it or prevent it. And I certainly have learned personally absolutely nothing from my lifetime of work.

I'm like incredibly stressed. I'm mostly good at telling you what's going to happen if you don't get stuff under control rather than how to get things under control. When I look at the stress management literature, I don't do it very often because I tend to get sort of agitated at that point, but broadly it works. It works as in you can lower blood pressure, you can lower cholesterol levels, you can lower subjective sense of health, you objective measures as well, with all sorts of interventions. objective measures as well, with all sorts of interventions. What do you see when you look at the literature closely? First off is you can't do your stress management on the weekends kind of thing. It needs to be a regular sort of thing. You can't do it while you're on hold on the phone for 30 seconds. You need to set time out for it. The benefits of

aerobic exercise, I don't know what the magic number is. These days about 20 or 30 minute blocks is a minimum to start getting the cardiovascular benefits. So it's got to be something like you stop things to do. So that's important. Let's double click on that. What you're basically saying is, because I think you're understating how much you know about this topic. Obviously it's something you know a lot about as seriously as we would take nutrition. And if you think about how many hours a week do you put into eating? I mean, even if you're shoveling food down your throat, it still takes quite a bit of

time. If you're going to exercise to the levels that have demonstrated benefit, we're talking about hours a week, not minutes a week. If you're going to make the difference between getting by on sleep versus getting restorative sleep, I'm not talking about the absolute amount of sleep. I'm just talking about the delta between those two. Think about how many hours that is. In fact, for the average American, that would work out to be about an extra seven to eight hours a week of sleep. And what you're basically saying is, if you want to combat this hypercord of salibia, dude, guess what? It ain't a 20 minute a week thing.

And in some ways, that taps into one of the 80, 20 rules of sort of mental health professionals. Okay, so you have this crazy stressful lifestyle. And there's just a bazillion things you can't say no to and you're just going 24, 7. And if you've gotten to the point of saying, this is crazy, this is not a quality life. I want to live a healthy quality old age. Well, I got to get this stuff under control. I'm going to start doing something stress management-y.

And if you've gotten to the point where in this lifestyle where there's a billion things you can't say no to each day You're saying no to them enough that nonetheless 20 minutes every single day you are doing this It almost doesn't matter what intervention you're doing you're 80% of the way they're already If you're managing to do that and that's very similar to this sort of amazing classic finding. You get people who were clinically depressed. And finally, finally, finally, they're going to do something about it and merely making a first appointment. Even before you've seen the person, people feel significantly better because you are finally saying, I matter enough to do something about this or I'm activated enough or I'm optimistic enough to actually go your halfway there at that point merely by doing something on a near daily basis.

So just on that logic, even though I don't know that this has been done, you would argue that 10 minutes of deliberate mindful practice of meditation daily would probably be better than one hour once a week. Absolutely. In part because if nothing else, if you do a daily seven times a week, you were sitting in the aftermath of having done that versus only one time a week, and an awful lot of what's most interesting about physiology and its impact on sort of mental health, things like that, is what's happening in the recovery period after something like that. In the same way, one awful hour long stress

or a week versus punctuated episodes of it throughout the week without question, the latter is worse because you've now got empty different times that you have to recover from having turned on the stress response, and that's where a lot of the damage occurs. You've now got umpteen different times that you have to recover from having turned on the stress response, and that's where a lot of the damage occurs. You know, I learned something about myself that's, you know, sounds so stupid because it's so obvious. Although, I don't think it's true for everybody. Email is a huge stress to me.

To be blunt, I hate it. That would be the kindest thing I could say about email. I really, a few months ago hit a true nader in my response, and I'm like, looking at these glucose levels going up, and I'm looking at these morning glucose levels. So even though my overall glucose level still look great, I mean, this trend was upsetting to me.

I'm watching my resting heart rate in the morning go up over the course of four months. It had gone up like six beats per minute. And if anything, I was in better shape, exercising more regular. I made this observation one day, which is how many times in a day do I stop to look at email, even if it's just a check one or two. And the answer was like 50. And every time I do it to your point, even if it's very brief, the after effect is not

that brief. So I could look at an email and see two stressful things, but it might sit with me for 20 minutes. So I tried this experiment, which is, I'm going to just check email twice a day, two 30 minute blocks of email. And I would say within two weeks, I just really felt better. It seems to me like we just have to figure out ways to figure out what those triggers are for us individually. There's probably some people for whom email doesn't trigger them at all, right?

There's probably, you know, for me, Twitter doesn't trigger anything because, A, I have a very narrow window that I pay attention to and it doesn't involve things that are aggravating like politics or religion or whatever. It's just sort of, I'm only really following science. So anytime I look at Twitter, I'm actually learning something kind of new and there, but I'm sure there are many people listening to this who would say, oh my god, if I spend an hour on Twitter, my blood pressure could be through the roof.

So it's like, everyone's got to kind of pick their thing. You said your type A, which obviously you are. I mean, you know what I didn't say at the outset when we started speaking, but you've won one of the most prestigious awards imaginable, which is the MacArthur award. And you won that about 30 years ago, right? That's impressive.

They don't give that award out lightly. So that's the one that's referred to as the genius award. And I know you're probably, like, your skin is crawling when I say that. My point being is you're an incredibly accomplished successful guy. It's not surprising you would describe yourself as a type A. What have you learned about yourself over the past 30 years or even longer going back to your first days in Kenya about what those triggers are for you and what you can do to lower your cortisol levels. Not surprisingly, if you hang out with people who are field biologists of any sort, and again, I've only been a part-time annual one over the decades, but nonetheless,

still think of myself as a field biologist. We're kind of a solitary tribe. I mean, during my peak periods of doing field work, I'm spending three, four months a year alone living in a tent where 12 hours a day, I wouldn't say a word to another person. Temperamentally, this is kind of who I've been for a long time. And there was always this ironic thing because I was sitting there studying these baboons

because I'm a primate social behavior. I'm interested in primates, social behavior, and there's big sort of piphony I had in my work that, okay, you're a social rank as a bad wound, that's something to do with your health, but much more importantly, as your patterns of socialization and social networks, and how often do you groom, and how often do somebody groom you, and how often do you groom and how often do somebody groom you and how often do you sit in contact with another bad boom or playing with an infant and then I you know finish the day's work and go back to my tent. So there was something ironic that I was like studying the health benefits of sociality, living alone and a tent large part of the year. Your wife is a scientist too

isn't she? She was, she kind of decided she was sick of it and she now directs a musical theater program, which is much more fulfilling for her. But at one point, my wife came along. Yeah, yeah, that's what I was gonna ask. And eventually family and, you know, kind of realizing, oh, I've missed out on an awful lot of what are really, like the wonderful worth

living for moments in life out of the sociality stuff. And that is a refusional sanctuary from the world's madness. And I could not have predicted as a 20 year old who had been planning to be a field biologist for a dozen years at that point, I could not have predicted sort of how much of my equilibrium at this point turns out to be due to interacting with the right two or three other primates, like being in love with them and stuff. That one was kind of a revelation for me. I am not the social being that I would have guessed I would have been back when. Which is interesting because having this discussion with you today, I can sense much more of your introversion than the first time we met when you were giving an unbelievably charismatic animated talk.

I don't know how many of us were there, maybe a hundred people, which is so interesting, right, because you would, I think anybody sitting in the audience would look at this and say, oh, that's the life of the party. But it's interesting that we can compartmentalize and separate those things, right? I mean, you couldn't get up there and you can do what you need to do, and you're at your happiest, I'm guessing, in the way you described it, versus in the aftermath of that talk, when a hundred people run up to you to ask you four questions each. Not to get too self-reflective or something, but I'm a fairly introverted person who does better with scripts and giving a lecture is a pretty structured script and having sort of an academic persona or whatever is another version of it as well. What year did you become a full professor at Stanford?

33 or something early 90s. I mean you live in San Francisco, so you're not making that commute every day, I hope. But I did for about a quarter century. Yeah, that'll hurt the court of salt levels, won't it? I use the commuter train, counter train here. So you could read and... I loved it. This was much of it. It was before cell phone. So you'd take it up at fourth and king and you'd just go, yeah, I used to make that ride all the...

I used to have a girlfriend that lived in San Francisco and I loved that train ride. And then you'd get off on your bike at fourth and king and you could go anywhere in the city. Yeah, exactly. I wrote half my book writing was on the train there. It's pretty weird when you realize that like one of your valid social communities are the conductors on CalTrain, sort of as you're watching them grow up on you and things like that. But yeah, no, that was, I was a big fan of train commuting.

So speaking about books, let's talk about your more recent book. It's about human behavior, which, you know, I mean, I can see based on this discussion now, how your interest would shift to that, what was the impetus for that research? Well, title is, behave the biology of humans that are best and worst. And sort of as we were talking about before, I closed my lab four years ago and stopped active research to sit for four years and write

this book. And it's basically trying to make sense of the biology of what is for me the most puzzling thing about us as a behaving species, which is we are simultaneously the most miserably violent species on earth, and the most altruistic and cooperative and empathic. And any given human is capable, depending on the setting of incredible gyrations, as to whether they are being wonderful or awful or in between where behaviors aware whether that counts as good or bad is incredibly dependent on what culture they happen to be doing it in. Just trying to make sense of the biology, I mean, totally boring biology is to like how your brain makes you do something like pull a trigger, like which muscle groups have been told?

Like that's like studying cockroach neurobiology. What's totally interesting is the fact that we're a species where sometimes pulling a trigger can be one of the most awful things a human can do. And sometimes it could be one of the most wondrous ones. If you're suicidally drawing fire from innocent people and you're sacrificing yourself or in one setting you put your hand on somebody else's and that could be a moment of incredible compassion or in another moment you do the exact same thing with your primate muscles and that's the first step of betraying a loved one of

just making sense of this contextual stuff about human behavior, which is hugely complicated. And the song and dance that I go through and nearly 800 agonizing pages in the book is, you're going to understand nothing about that. If you've concluded, aha, we now know this is the part of the brain that explains everything. Or this is the neurotransmitter, or the hormone, or the gene, or the child. Instead, to make sense of human behavior, you got a factor in what your neurons did one second ago. But you got a factor in the environmental triggers of that 30 seconds ago. And you've got a factor in what your hormone levels were like this morning. And what neuroplasticity you've done over the last two seasons

and what your adolescence was like in your childhood, in your fetal life, in your genes, and amazingly, what sort of culture were your ancestors inventing centuries ago, because that influenced the way you were raised within minutes of birth and what things you value and what things your amygdala does or doesn't respond to and all the thing of that. What sort of ecosystems produce different types of cultures and then finally evolution.

And why we're in some ways like chimps and in some ways like bonobos, but we're not chimps. We're not bonobos. We've solved our own special evolution. Like, if you got to understand this stuff, it's everything from one second before to a hundred million years before, and all these levels interact, and it's complicated to sell. When people ask the question, which I'm sure you've heard this a hundred times, and you hear people asking all the time, are we innately good or bad? That question doesn't really permit the level of nuance you're describing.

The answer is yes. Yes. Exactly. And what's most startling about us is most of us have the capacity to do something that we would be stunned and sick and that we were capable of doing it. And most of us are capable of in some circumstance of doing something that is so damn heroic. And most of us spending most of our time doing things that are ambiguous and multi-layered and full of ulterior motives and what's really going on there.

And you look at the worst of us and the best of us, and there's not a whole lot of really reliable predictors beforehand. And how much of this, like, you know, you wrote a little bit about PMS. So when I think about PMS, I think about it purely through the lens of the endocrine system, right? I think of it purely through the lens of when a woman

is in her loodial phase, that progesterone level has to rise for the placenta, and then of course, virtually every time, it's a false alarm, you don't need it, you shed that lining, and that progesterone level comes crashing down. And it's this crashing down a progesterone that has always interested me, why two women could experience the same we can measure progesterone levels

throughout the cycle. And we could know that at day 22, two women could have the exact same progesterone. And on the first day of their mencees, they could have the same progesterone. So you know they had the same peak to valley. And yet two women can experience that in two totally different ways. Now I've thought about that through the lens of progesterone receptors, and the way we sort of talked about the cortisol stuff, is there something else to that that you layer on top of that that is even more subtle

about those differences? Yeah, tons of this sort of additional insights. Here's one example that comes completely out of left field, and this was actually my wife's thesis research on baboons. So your female baboon and you're coming up on your period and we could frame it as you just did. Here's two females who are both about to have their period and they have the same exact progesterone levels

and as soon as they start menstruating, progesterone drops in exact same way. And one of them is a totally irritable, awful jerk to all the other females around her for three days afterward. And the other one is not. The other one withdraws and becomes socially isolated. Okay, what's the difference? It sure can't be progesterone levels.

So it's probably not gonna be progesterone receptor levels. It's one of them's high ranking. She could afford to be a jerk to everybody else and get away with it. The other one's low ranking. Oh, it's not just your hormone levels. It's what sort of position in your society you have, even if you're a baboon.

Or now you look at humans, and depending on what sort of culture you're in, are you in an individualist culture or a collectivist one, individualist, the United States, poster child of individualist, thinking collectivist, 99% of the research has been done on East Asian cultures and how you somatisize your mood shifts and your physical shifts during your period differs in collectivist versus individualist cultures, how irritable you become. Not because there's a difference in how much

of negative affect your feeling during the time, are you in a culture where it's culturally acceptable to bitch and moan to all your best friends when you're not feeling well? Or are you in a culture where when you're feeling lousy, what you're supposed to do is reach out affiliatively and reify your like social values? And how much of that do you think is also genetic? So for example, I mean, even though I'm not a gynecologist and therefore don't see a lot of this, I see enough to realize that women will often say my sister and my mother either go through or went through the same feelings.

And of course, as you describe, there are so many different variants. The stereotypical one is the, you know, the sort of the nasty phenotype, but actually the one that I think might be more prevalent is the sadder phenotype, the more emotionally distraught, just emotionally labile, but in a non-aggressive way. That's probably the phenotype I see more, easier to cry or something like that. So how much of that do you think is heritable in the way that eye color or some other aspect of body habit is, or even depression is quite heritable.

Versus the ecosystem you're in purely environmental. Well, the answer is you really can't choose one of the other blah, blah, but if you could only manipulate one, which would be the first one, and I'm definitely of the school of genes get overrated in terms of their impact. And, you know, a gene affecting your eye color, it's okay to use words like determine. And it's probably not even 100% accurate. But when you get to genetic influences

on all the interesting stuff and behavior and our internal lives and all of that, yeah, gene to important, but overwhelmingly, these are genes that modify vulnerability, vulnerability to certain types of environments. Okay, so for example, you bring up depression and catastrophic pandemic of that. And, you know, there's a whole shopping list by now of genes that have been implicated. And probably the single most important one, it's called the gene for the serotonin transporter and serotonin SSRIs, pro-zacol, and those serotonin is just like right in the middle of what

we understand about the neurochemistry of depression. And it turns out this serotonin transporter gene comes in a few different flavors, a few different genetic variants, and a ton of basic research, rats, monkeys, etc. suggested that if you had one particular variant, you were more at risk for major depression. Okay, so this classic work, this guy had Duke, offshore on caspies, sort of a god in the field, goes out and he follows like 17,000 people from birth up to age 25, or so he's got genetic information on them.

And he's able to ask this critical question, okay, if you have the quote, bad version of this gene, by age 25, are you more likely to have a history of clinical depression? And what's the prevalence of the gene approximately? It depends on the population. In his population? His was a mixed one, but Westernized Western European populations, I think it's got about

a 20% incidence. So the question then is of those 20% how many go on to get depressed, of the 80% how many go on to get depressed? The answer is very likely going to be it's not a one-to-one mapping. It might be an increase in risk by some factor. And what they saw was overall there was no increase in risk having the bad variant. However, if it was coupled with a lot of childhood stress, you had about a 20-fold increase in the risk. So just to be clear, on aggregate, there was no difference. The hazard ratio was one for with gene versus without.

Because of a ton of variability. But if you wanted to amplify it, take that gene and expose it to childhood stress or trauma and you almost assure depression. You get a massive boost in predictability. Look at people without the scaryant vulnerability variant and look at the same severity of childhood stressors and loss and you got a moderate increase in incidence of depression. These folks massive order of magnitude

multiples of that more increase there. What that tells you is this is a gene whose variance alter how readily you deal with experiential kicks in the ass is growing up. And it turns out these different variants are regulated in different ways by glucocorticoids. Aha. So there's a stress angle, all of that. The same way, there's another gene for the people who are interested in the genetics of aggression. The same way, there's another gene to the people who are interested in the genetics of aggression. This gene model would mean oxidase and it comes in variants and it's... And there's a class of drugs that targets these perceptors. Yeah.

Again, a ton of basic research had suggested, ooh, there's a scary variant of it, which if you have it, you are going to be more predisposed towards violence. And in fact, the same group working with the same population, massive data set, winds up showing, just having that variant doesn't get you a higher risk of antisocial violent behavior by age 25. If and only if it was coupled with abuse, childhood abuse growing up.

Oh, if you didn't have the scary variant, childhood abuse, a little bit of increased risk, have this variant with the abuse and it was virtually the same figure as with the serotonin transporter gene, huge boost and very over and over the genes that are interesting when it comes to this stuff. These are all genes about vulnerability and potentialities and tendencies that are emerging only in certain environments and not in others. The factors are inseparable. It makes me think of the apoe geneotype, which is linked to Alzheimer's disease. And there we see that there is a difference. About 25% of the population carries at least one copy of that gene, and they represent about two-thirds of the cases of Alzheimer's disease.

It's not a deterministic gene, but it does increase risk. Now of course, you could argue that maybe in a decade or more, we will be able to say something very similar about ApoE, which is it's not remotely deterministic. It only gets turned on when x, y, and z happen before this period of time or in absolute. And of course, we don't know what those things are right now. At least in the examples you gave, you could say, well, trauma or childhood, you know, some event in childhood was the trigger.

And if you're seeing a 20-fold difference, it's pretty clear that you found the trigger. Nonetheless, there's still variability to explain after that. But yeah, it's pathetically that counts as virtually state of the art for understanding the modifying factors. And it's going to be that way. In any time you do these like GWAS massive fishing expeditions and you come out with 300 genes are implicated in a trait that's as boring as height, 300 genes, which you put together all of your knowledge of the variation in them and then you give individual, and you have like 4% predictability of their height. You know, Christ, if you're talking about genes

for propensity towards feeling poignancy, or genes for anything that's interesting, it's just not a chance. Even if you just limit yourself to diseases, you know, of the 20,000 genes in our body, you can really only point to about a hundred that are directly this mutation means this disease. And they're all pretty esoteric, right? It's all like inborn errors of metabolism and certain things like that. But when you start to talk about the complex diseases like Alzheimer's disease, even as predictive as the APA we for is

it's not even close to being enough to understand it. And I think, yeah, it's funny. When you talk about it through that lens, you realize the importance of environment, which is, you know, through a specific statement, obviously, you said something a while ago that I made a note of because I wanted to come back to it. You talked about the effective glucocorticoids on the hippocampus, and not only how harmful it was for memory consolidation, but overall cognitive impairment. And listening to you talk about that was exactly the way Matthew Walker, Berkeley, speaks about sleep deprivation and its impact on the hippocampus, which then makes me wonder,

I assume it's been well studied that, you know, when people are sleep deprived, we see greater elevations of cortisol. Do you have a sense of what the evolutionary basis of that is? Because it seems counterintuitive. You would think even evolution would want that to be in the opposite direction. I mean, the only explanation I can come up with is if you're sleep deprived, you're assuming that there's a reason for it that's good, and therefore you want that. Of course, not with any of the fact that higher cortisol will then prevent that. I think that's probably the best sort of piece of tealiology for that.

Yeah, if you're like a basic mammal, which means either you are emphatically diurnal or emphatically nocturnal, and if instead you're wide awake eight hours into what should be the 12th, this does not happen by chance. The odds are you have something stressful going on. I think that's the logic of it. Turns out the stress, sleep, sleep quality cortisol cluster of interactions, even more subtle, incredibly cool study. This was a science paper some years back that, okay, so as we talked about the circadian peak of glucoricoids around the time you wake up, what's interesting is about an hour before you wake up, levels begin to rise, telling you something, a subtle point, which is

a lot of glucoricoid actions, are not for dealing with a stressor that has already commenced, but can be preparatory. So the preparatory stressor is having to actually get up and get out of bed and start functioning the stress, and an hour before people wake spontaneously, glucoticoid levels are elevating. Now in the study, what you do is you take a whole bunch of volunteers, you're sleeping, and you see the preparatory rise, all of that, what you do is you take a whole bunch of volunteers who are sleeping and you see the preparatory rise all of that and you tell them tonight we're doing something different. I'm going to wake you up at four in the morning And what you see is around three o'clock Gluquaticoid levels start rising. Okay, now you do something even more interesting. You say

Okay, tonight I'm not going to tell when, but I'm going to wake you up at some point during the night, and that's the end of your night's sleep. And the person is about 90 minutes into their sleep stage and all of that. And cortisol rises and stays high for the rest of the night. You get one sleep cycle. And then the adrenal gland says, that's it. I'm on ready alert. Yeah, exactly. So not only is it bad not to get enough sleep, not only is it bad if the insufficient sleep is fragmented, but the worst is if it's fragmented unpredictably. And that's like every medical resident in history. It's the first thought I had actually when you said that which was every night of call you have this

pager and you're in this call room and you just want so desperately to sleep for an hour or two hours, three hours. I remember as my residency went on, the degree of sleep deprivation got greater and greater that the steps I had to take to ensure I wouldn't sleep through a page got greater and greater and I'm not making this up. I don't think I've ever told the story before. It's so ridiculous. I used to use this really heavy paper tape and tape the pager to my head, my forehead at full volume because you would get both the sound to your ear and then you'd get the transmission, you know, through the bone. But imagine laying in bed with tape wrapped around your head holding a pager on your forehead in anticipation of what's coming, not knowing when it's coming. It could be in five minutes or it could be in two hours.

You know you're gonna wake up. Yeah, I'm guessing that wasn't great sleep. No, that's like wildly destructive. And what do you know? It turns out if you have elevated glucoticoid levels while you're asleep, you have less delta sleep time, which is the restorative stuff. You make less adenosine stores in your brain during. So even if you manage to go to sleep, if it's under the, I could be a sleep for two hours, now or 30 seconds, the sleep quality is going to be horrible. This interplay becomes more pronounced. What about cancer?

What role do you think stress plays in cancer? And do you think it's mostly medillated through the immune system? I mean cortisol can be quite damaging. Yeah, a hugely, hugely controversial subject. There is a common perception that stress can play a very substantial role in the onset of cancer in coming out of remission and rates of tumor growth and such, sufficiently so that there's been all sorts of studies where you ask cancer patients, what do you think is the cause of your cancer and stresses and variable way up there.

The actual evidence for a role of stress in causing cancer, bringing it out of remission, accelerating tumor growth is very, very minimal. There's been a remarkably small number of good prospective studies of humans that have really, truly ruled out all the confounding factors. When you look at the animal studies, what they typically involve is you experimentally induce a tumor, you inject transform cells, you give a carcinogen some such thing. My lab back when did some of that work under those circumstances, you can accelerate the growth of a tumor, but those are circumstances of cancer acquisition

that are virtually irrelevant to human cancer. And the other question is, can you do it without perturbing other things? So for example, if you go ahead and stick the tumor into the mouse and apply a stress to it, it seems that that by definition will alter some other parameter, what it eats, how much it sleeps, the quality of it sleeps. So it becomes difficult to disentangle cortisol. I mean, I guess the only thing I can think of is what does the experiment look like where you take the mouse that experimentally has the tumor and you just start injecting more glucocorticoid? So in other words,

you don't actually increase the stress level. You just increase the readout state of stress. You accelerate the tumor growth. We did one study showing that as soon as cells become transformed, they upregulate the glute-4 glucose transporter, and that's the one that's further upregulated by glucoticoids and target cells. So you're just shoveling energy over those cells. Yeah, but these are- Which preferentially consumed glucose anyway, just given the number of them that fall by the warberg effect. So to me, even though that's very mechanistic and artificial, that strikes me as pretty reasonable evidence that cortisol can play a role in cancer.

I mean, I guess it's going to be much more difficult to disentangle that in the real world. Yep. And again, these are types of cancers where this was virally induced transformation of cells that are then transplanted in very artificial systems that turn out not to be terribly applicable to human cancers. And what you wind up seeing then, okay, yes, gluc corticoids can be potently immune-suppressive. Usually by the time you have a tumor growing, that's long past the point where it's an immunological problem.

It's now, can you keep the tumor from growing a whole bunch of capillaries that will feed it? Can you keep it from stealing all sorts of energy? Can you keep it from turning off cell death programs? It's no longer in the immune realm. So it seems that there'd be hard to make the case that acute bouts of stress can really have any impact because, you know, yes, sure, you can acutely disrupt the immune system and maybe get sick, right?

That, you know, I could explain why you might get a cold under a period of great stress, but not necessarily cancer. And what that wants, meaning is that should be a massive, massive take-home message for anyone who is predisposed towards thinking, ooh, stress caused my cancer. Too bad I didn't have better priorities in life. Now I know who's faulted is. That sort of thing. And it certainly make you damn cautious if there's some highly credentialed quack out there who is selling a stress management will stop your tumor, will make a disappear entirely, and you'll watch your wallet at that point.

All that being said, there's been some wonderful work, and a lot of this was pioneered by a Stanford colleague of mine, David Speagle, who showed that things like supportive group therapy among cancer patients enhance a survival. So what do you think is the mechanism of that? Okay, this was when he first published this in the late 80s, this was front page news. I remember this. I mean, I don't remember it when it was published, but I remember learning about it in medical school.

Massive finding. And one is immediately tempted to release there's a biology type like me to come up with a biological explanation along the lines of what you proposed. Okay, supportive group therapy, you're less stressed. So you don't secrete as many glucoticoids and therefore you're not having loose adverse effects of it when your immune systems,

you're better able to fight the tumor, you live longer, trull on this. And lower glucose levels and lower glucose and lower insulin and lower IG. If you could, you could come up with a complete biological. And in general, those studies have shown that pathway does not occur, Spiegel and I did some of those studies. So what's actually going on, something which if you're a nuts and bolts reductive biotype person is terribly disappointing, but is so interesting

and important. People, when they have supportive cancer therapy with other people going through the same hell, they become more compliant when they're medical regimes. They're more likely to go the extra round of chemo because everybody else is cheering them on saying, I didn't want to do it either. And they're more likely to take the meds that make them nauseous as hell. Have you eaten today? Me neither. We're going to eat right after we're done with the group.

Have you taken your meds? You're going to take them right now. People become more compliant. And that was very hard to demonstrate because what cancer patient ever wants to admit to a researcher, actually, I skip about a third of my meds because they make me feel so damn sick. They're saving your life, would it? It's in some ways a dark, dirty secret in cancer therapeutics. How much people diverge from their optimal treatment regime, because the treatment regimes are sheer utter hell. When you're surrounded by people who are going

through the same thing and understand, you're more likely to be compliant. I think that winds up explaining an awful lot of that effect. So when you look at cancer, atherosclerosis, and cancer, atherosclerosis, and neurodegenerative disease. It seems to me that the direct lines of evidence for the damage of hypercordisolemia and the accelerated stress response are probably most demonstrated in cardiovascular disease and atherosclerosis, vis-a-vis several mechanisms, not the least of which is hypertension, both macro and microvascular, but also through endothelial disruption. Adhesion of cells and sludging and yeah, it's the best understood realm. Cancer is probably the weakest realm. I would expect that it's playing a role in dementia, but again, this probably gets to the layer of susceptibility, right? There's probably an isolation, maybe this wouldn't play a

role, but in combination with other factors, it would. And it seems that, for example, we know that cortisol inhibits melatonin secretion. So even if you take two people who have the same amount of blue light reduction, which should therefore stimulate melatonin, the one with hypercortisolemia is going to, and we actually measure this, right? We can measure overnight urinary cortisol and overnight urinary melatonin. You can see this association quite strongly. Well, melatonin, it's a pro-nerogenic molecule. So having less of that is less restorative to the brain, even beyond its important role,

which is sort of removing the brakes on being awake. So what other lines of evidence do you see beyond what you've already described at the developmental stage now later in life? Basically everything we talked about with the hippocampus applies in the adult brain as well. And it's the first place we tend to see changes. And it was the first area of research, first evidence for stress damaging the hippocampus and hippocampal dependent memory type

stuff, late 70s. I mean, that was really the first domain and superb studies from a number of groups. And I had my two cents and that would return also showing you could accelerate aspects of hippocampal aging with lots of stress, lots of glucoticoids, extensive neuron loss, extensive memory problem, extensive reactive galeosis, etc., etc. Next big outpost that people began to appreciate in adult brains was derivative of what we talked about before, which was the mictula. I was just about to say, is there a direct correlation,

I guess, between the MIGDLA size and dementia? What you see instead is the syndrome where it's most demonstrated as PTSD. You see expansion of the MIGDLA and you see atrophy of the hippocampus and glucocorticoids probably play the driving role in both. So in the MIGDLA, like the hippocampal story is stressing, corticates, screw it up. Neurons don't work as well. Networks don't work as well. The overall size decreases. You had atrophy. And the amygdala, it's

the exact opposite story. Neurons work better than they should. Neurons become more excitable form denser networks. The amygdala gets bigger. What's that about? The problem with chronic stress is your memory goes down the tubes, hip campuses, and working as well as usual. The problem with chronic stress and the amygdala is it works better than it's supposed to. And this is the link between stress and anxiety disorders, stress and fear, stress and all of that. Next sort of outpost that people started looking at was the dopamine system in the brain. And dopamine neurotransmitter,

most famously associated with reward, pleasure, cocaine works on the dopamine system, a much more accurate subtle picture of it is dopamine is actually more about the anticipation of pleasure than it is about pleasure itself, and about goal-directed behavior you're willing to do in anticipation of reward. But then a whole literature showing what distress and glucoticoids do there, they mess with the dopamine system. It's less clean of a story than a MIG-DLABOR hippocampus, but in

ways that predispose towards the two big psychiatric diseases of screwed up dopamine systems, number one, addiction. More vulnerability to addiction, harder to get off of addictive substances, number two, depression. Depression is a disease of on a certain level, dopamine depletion. It's a disease of inability to feel pleasure and hedonia. And that's the neurochemistry of the link between chronic stress and why that increases the likelihood of the first three, four episodes of major depression.

What for me is the most exciting area is one where if I was starting over, you know, forget the hippocampus who cares about like how many digits you could remember backwards or whatever, the most interesting domain is turning out to be what's directly glucoticoids to to the frontal cortex. Judgment, impulse, control, executive function, long-term planning, strategizing, and it turns out virtually every bad thing cellularly that's dressing glucoticoids doing the hippocampus, they're turning out to do in the frontal cortex as well. And what does that begin to explain in this entire world of why it is during moments of extreme emotional arous, so especially aversive ones, why we make terrible, terrible decisions

that seem brilliant at the time. And you spend the rest of your life regretting it because impulse control, you're a miktola overpowers your frontal cortex at those times, your amygdala has a lot more talking to your motor systems than your frontal cortex does. It's the reason why judgments and impulse control become terrible when we're frazzled.

It's also looking like as a side story with that. It's one of the reasons why when we're very stressed, it's hard for the frontal cortex to do one of its harder jobs, which is to take the view of the world from somebody else's perspective. Empathy. Empathy, exactly. Some research on animal models of empathy, and this was worked with this guy at McGill,

named Jeffrey Mogel, and we're collaborated with him, showing in both rats and humans, you're less empathic towards strangers when they're in pain. And if you block glucocorticoid release, you don't get that effect anymore. Glucocorticoid, the stressfulness of dealing with scary novel humans or scary novel mice, if you're a rodent, glucocorticoids narrow your window

as to who counts as an us and whose pain registers and things of that sort. So for me, you know, it's incredibly interesting if you're stressed and suddenly your SAT scores plummet, the fact that stress makes people crappier to each other and less empathic and more parochial and more xenophobic and more impulsive with the worst of our impulses, that's the stuff that really interests me these days. Everything you just said, Robert, is almost a call to action in criminal justice reform.

I've done a podcast on this topic where it was very fortunate to go into a maximum security prison with a program that is really there to do incredible, rehabilitative work led by this woman named Catherine Hoek. It's a humbling experience. There's a game that we played about halfway through the day called Step to the Line. This is a game that's used to basically identify

the vast difference between those of us who are volunteers. Like in other words, the role of luck in our lives versus the gentleman who two-thirds of these men are never going to get out of prison. One man had even spent more than half his life in solitary confinement, his total life. So it starts with these questions of step to the line if you grew up in a home that had two parents and, you know, of the volunteers, you know, 60% step to the line of the inmates, five step to the line, right? Step to the line if you grew up in a home where there were more than four books.

You can imagine the disparity. Step to the line if you saw someone die with your own eyes before this age. I mean, and it's a very emotional thing to go through because as this game is unfolding, you're just, you're feeling more and more fortunate on the one hand because you realize, if not for the grace of this luck. And at the same time, the empathy you have for these men who have done the most heinous things grows. And you start to realize, boy, there's a fine line between those of us on the inside, those of us on the outside, because everything you said really resonated when I was thinking about some of the stories the men told us, about

the decisions that they made. And there's this one part of the exercise that's incredibly emotional where you're partnered with one guy. So it's one volunteer, one inmate. And you were each telling the other person the greatest regret of your life, the biggest mistake you've made. And hearing some of these stories, it's not to justify anything that's been done, and it's not to say that there shouldn't be consequences for it. But a lot of these things that people have wound up in prison for are really impulsive, horrible decisions, as opposed to decades of sinister

planning. It's one thing to look at what Hitler did. It's hard to argue that anything that he did that was bad was impulsive. It's quite another thing when you look at someone in a gang-related incident where this guy gets shot and you're going to shoot this guy back or this guy's about to shoot you and you shoot him. And yet that type of drug-related violence is disproportionately represented in, certainly in the US penal system.

And then to build on what you said, it's not clear that the environment in there is reducing cortisol levels to the level that would enable rehabilitation, which is really the thesis of, and a lot of people I'm sure listening to this are thinking, why would you feel empathy for these folks that are in there and why should society care about them? But the reality of it is, if they're going to get out, you should care. That says nothing of maybe the higher level that you should care, which is the injustice of it.

But even if you took a purely selfish view, a non-trivial number of these men and women are going to get out. So wouldn't you rather they get out and function better? And yet it's really tragic to see this. And I know two people actually very well who spent a great deal of time in prison, one of whom I interviewed on this podcast, his name is Corey McCarthy, and it really strikes me as the exception and not the rule that people are able to emerge from that environment and go on to be successful outside.

It's a system that is so, so broken. Any study the last century and a half, some worth of neurobiology and genetics and child development and all of that and the notion that we are free agents of our action is so destructively misplaced. I'm sure you're familiar with the work of Sam Harris. Sam has been one of the most interesting forces in my life at getting me to really even question this notion of free will. And once you realize that free will may not even be yours, it takes luck to a new level. It's something I spent a lot of time thinking about now.

What advice would you offer somebody who is interested in the neurobiology of stress or behavior and who wants to be able to look back when they're your age and be as, you know, maybe accomplished as the wrong word. I don't want I know you sort of bristle at that, but to have made as many contributions as you've made. I mean, what in retrospect was sort of the secret to being able to pursue your bliss and be as successful as you've been and look frankly to be where you are and to still have the passion that you have for what you're doing, which to me is really the marker of success. It's that you're sitting here saying, there's this other problem. And I, you know, like I could spend, you know, the next 20 years just thinking about that. How do you think about

how you've done that? Just damn luck. Every bit of neurosis, every bit of affective instability. I've got every child to trauma, I've got tucked away. I've titrated in just the right way that I've turned it into more productivity and incredibly lucky in that regard. My capacity to sublimate a motion into intellectual pursuit, into really, really, really wanting to understand something, into I've just been very lucky on that regard. I've gotten just the right levels of all sorts of like tumult that have synergized most productively. In other words, just huge amounts of luck,

in other words, just huge amounts of luck, huge amounts of luck, and at least now coming later in life, and increasing capacity to more carefully try to analyze what cost each type of ambition comes with. Hmm, say more about that. I don't know, I don't know. This had much to do with my closing my lab four years ago. The big booming lab with lots of people and all sorts of labs around the world. We were going to kick the asses of by getting the answer to this or that. And you know, if you're raised in the right sort of rarefied ambitious world of biomedical research at age 25, you've got a list down to the floor of the disease as you're going to vanquish and the problems

you're going to solve and all of that. And you know, getting to that point in life where you're realizing it's not going to happen. Is that what actually happened four years ago? Was it that much of a cerebral realization or was it combined with other factors? You've described obviously having this network of people around you who matter the most. I mean, it was part of it just thinking, I haven't spent enough time with them at the expense of this or was it the this problem is enormous and when, you know, a thousand years from now, whether I worked this much harder or this much less It won't have altered the trajectory of x was like I mean how much of it is all of these?

Holy love yeah family growing real fast as they tend to do Realizing your best work was decades behind you realizing there's This book you want to write and where the only way you can do is to just sit for really long stretches, Kenyan fieldwork having collapsed a few years before body feeling older limits to how many 80 hours of work a week you can do, all of them converging.

What did, I mean, it's such a cliche question. What advice would you give the 25-year-old Robert as he was just finishing that PhD at Rockefeller? BLS ambitious. Well, I think on that note, which by the way, I think is some of the greatest advice one could ever get and receive. Those of us who are still on the climbing ambition curve should do everything to listen to it. I want to thank you so much for taking the time to sit down with me. And more importantly, I think for just all of the work you've done and you're continuing to do. Thank you so much.

No, thanks for having me on. This has been fun. It's the wrong word, but stimulating, good. Glad we did this. Thank you for listening to this week's episode of the drive. If you're interested in diving deeper into any topics we discuss, we've created a membership program that allows us to bring you more in depth, exclusive content without relying on paid ads. It's our goal to ensure members get back much more than the price of the subscription. That end, membership benefits include a bunch of things. One, totally kick ass comprehensive podcast show notes, the detail every topic paper, person,

thing we discuss on each episode. The word on the street is nobody's show notes rival these. Monthly AMA episodes are asking me anything episodes hearing these episodes completely. Access to our private podcast feed that allows you to hear everything without having to listen to spills like this. The Qualies, which are a super short podcast that we release every Tuesday through Friday, highlighting the best questions topics and tactics discussed on previous episodes of the drive. This is a great way to catch up on previous episodes without having to go back and necessarily listen to everyone. Steep discounts on products that I believe in, but for which I'm not getting paid to endorse. And a whole bunch of other benefits

that we continue to trickle in as time goes on. If you wanna learn more and access these member-only benefits, you can head over to peteratiamd.com forward slash, subscribe. You can find me on Twitter, Instagram, and Facebook, all with the ID, Peter Atia MD. You can also leave us a review on Apple Podcasts or whatever podcast player you listen on.

This podcast is for general informational purposes only. It does not constitute the practice of medicine, nursing, or other professional healthcare services, including the giving of medical advice. No doctor-patient relationship is formed. The use of this information and the materials linked to this podcast is at the user's own risk. The content on this podcast is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Users should not disregard

or delay an obtaining medical advice from any medical condition they have and they should seek the assistance of their healthcare professionals for any such conditions. Finally, I take conflicts of interest very seriously. For all of my disclosures and the companies I invest in or advise,-date and active list of such companies. you