The Infinite Monkey Cage - What Makes Science a Science?

Episode Date: July 15, 2013

What Makes a Science a Science?Brian Cox and Robin Ince are joined by "Bad Science" author Ben Goldacre, neuroscientist Sophie Scott and broadcaster Evan Davis to ask what makes a science, a science. They'll be asking whether the scientific method can be applied to topics such as history and politics, and whether subjects like economics and social sciences qualify as science at all.

In our new podcast, Nature Answers, rural stories from a changing planet, we are traveling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share stories of how they are thriving using lessons learned from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcasts. This is the first radio ad you can smell. The new Cinnabon pull-apart only at Wendy's. It's ooey, gooey and just five bucks with a small coffee all day long.

Taxes extra at participating Wendy's until May 5th. Terms and conditions apply. This is a download from the BBC. To find out more, visit bbc.co.uk slash radio4. On my left, a man who was hotly tipped to be the new Doctor Who, with few people of course realising what a disaster that would be.

When you first see Scarrow, it seems like a rocky outcrop plagued by war, but the beauty of the dead sky is wonderful. Look at this dalek here. Oh, dear, I seem to... We'll have to regenerate again. It's Professor Brian Cox. And on my right, a man who recently visited a hypnotist to be regressed and discovered that in a previous life

he'd been a loose collection of mud, puddles, a dead starling, a cardigan, and a crumpled copy of New Statesman. Which are necessary and sufficient elements required to build a Robin Ince. Now this week we're going to be asking what makes a science a science? Careful observation and the application of common sense. Good night.

No, to be fair, we are going to try and deal as much as possible. I mean, for instance, Brian, if you're really honest, you know, what really is the difference between, say, astronomy and astrology? Really? Ow! Ow! Ow! Ow! Ow! Ow! Ow! Name's Sherry Bryan.

So, to help us decide what is a science, what is a pseudoscience and what might just be humanities with a graph, we have... We have three possible scientists and a physicist, who, of course, is clearly a scientist, because physics is the emperor of the sciences, the most regal and exalted pursuit

to which any sentient collection of atoms in the universe can aspire. A life spent... I didn't... When did you go back into the office? The, um... Nyeh, nyeh, nyeh, nyeh, nyeh, something star stuff. So, our first guest is a doctor, broadcaster and author of the best-selling Bad Science, in which he criticised pseudoscience in all its guises, from homeopathy to qualification-purch purchasing, poo-siving nutritionist. I'm not saying who it is. I didn't say who it is.

Look at my poo! I'm not saying who she was. Oh, I've given some of it away. Anyway... He also has recently written another book, Bad Farmer, which is also a bestseller, and he spends much of his life scrutinising science, looking for the bad amongst the good. If he can turn it into a graph, he will. He is the good-time epidemiologist who is Dr Ben Goldacre. Formerly the BBC's Economist of Choice,

now presenter of the Today programme, he has a degree in PPE. That's Philosophy, Politics and Economics. Philosophy are going together wonderfully with the other two, as it helps provide metaphysical alibis for the cock-ups. It's Evan Davis. And finally, we have our favourite rat tickler of choice. And, of course, by rat tickler,

what I actually mean is someone who tickles rats. Of course she does. She's a neuroscientist. She researches the evolution of language and the science of laughter and sometimes combines the two by making jokes about Noam Chomsky's universal grammar. It is Professor Sophie Scott. APPLAUSE Professor Sophie Scott. Right, we are going to start off with a very quick kind of panel quiz,

which we don't normally do, but which I'm going to throw out to you various different ideas and subjects and see whether you think they are a science or whether they're not a science. And then we're going to look at the definition of science. So I'll start with you, Ben Goldacre. So first of all, social science, is it a science? Well, I... So I wouldn't define a science by the things that you're looking at. We're not asking you to define a science.

It's the quick-fire yes-no round. But I don't think you can, because it's about the tools you use rather than the things that you're studying. So some social science is working. Evan Davis, social science. No, it's not a science. It's a social science. The clue is in the name. That's the answer we were looking for.

So, Scott, Freudian psychology. Not a science. Evan, sports science. Yes, that is a science. Ben Goldacre, Scientology. Because it does sound science-y, and there's rockets and stuff in it. I'm almost afraid to pass comment. Evan Davis, economics.

I hope I'm not here to defend economics all night, because if I am, I want to be on the other side. I want to be on the other team. No, I think economics isn't a science as this programme defines science. Well, we're going to find out what the definition is. And finally, Sophie, judo, science or not science? Oh, definitely, yes. No, I don't think it's a science. That was correct. Well done, you're in the lead.

So, Brian. Yeah, I think we should go along the panel and get a definition of science from your perspective as succinctly and precisely as possible. I'll start with Dr Ben Goldacre. What is a science? Well, I guess alongside all the obvious things like testable hypotheses, I think it's really important to be clear that it's about the tools you use

and not the things that you're studying. So almost all the interesting things that we're likely to talk about, like, for example, evidence-based medicine, which I aspire to practice, that's a mixture of craft and judgment and also using evidence. So when people pretend to be doing science and very obviously do that wrong, then you can distinguish between a science and something that's not science. And where things drift into more problematic territory, I suppose, is where everybody is doing it badly, like, for example, homeopathy.

But actually, to be fair, in evidence-based medicine, most of us do it badly to a greater or lesser extent. I think it's really difficult because you have to say, is the science what we aspire to be or is it what we actually do? So essentially what you're saying is you know what a science isn't. Which is homeopathy, essentially.

Well, I suppose... Apart from that. First of all, it's a set of tools rather than a domain of activity, and also I think we have to be clear about the aspirations of science and the reality of science. Bang on. Bang on. I'm sorry, I just wanted to say that. I think it's absolutely bang on. It is not a subject. Which is why your opening quiz was obviously a category error,

because that's a philosophical term. Robin's quiz, Robin's quiz. But it was a category error, because none of them are always science, and none of them are never science. Oh, well, no, some of them are never Scientology. Science. Judo.

Anyway, so, Sophie, how would you define a science? And, again, you can be as personal as you wish. I'd say going along the sort of similar lines to Ben, for me, science is a process, it's a thing you do, and you could be applying the approach of science to history or whether or not homeopathy works. It would still have elements that were in common, aspects of how you're weighing your evidence,

how you analyse some kind of objectivity objectivity i guess is something you're aspiring to so it's a way of finding out about the world that in the process of doing it that way helps you define certain properties of what it is you know once you know it at the end and it's not a job of sort of i don't know finding out what's true and what's not true until we know what's true and we stop doing the science it's a continuing process most of the stuff we're doing now will turn out to be wrong one day because it will move on it's not a thing with an end point which is good because you know i'd like to at least work to retirement well that is it's interesting because some people would say and i think this is kind of

a good definition which is you know science for instance not finding the right answers but it's finding the least wrong answers and it's a continual path i think think it was karl popper at one point someone said he became so intelligent when he was old. I mean, he was always very smart, but he got to a level of intelligence where he didn't know what was right, but he could always tell what was wrong. I think there's a kind of certain... Again, that to me has a sense of what scientific imagination is trying to achieve. Yeah, it's not about truth, it's about finding out information.

And you could find out information that's more or less appropriate once you've found it out. You might devote all these tools to finding out something utterly inane and uninteresting to everybody. And the larger process of science will... But enough about chemistry. Oh, did I just say that? Why do you insult the chemists, the ones who can most

easily wound you? Evan, I wonder, I mean, you've agreed with Ben, but I wonder if you have a kind of, you know, what your personal take would be on... Well, it's about keeping the fairies out, isn't it? It's about not looking for explanations that say, er, don't know, it's a fairy that holds the whole thing together or the world sits on the back of a pile of fairies

on the back of a tortoise. It's about it's about having a curiosity that relates ideas in the head or theories with the real world i mean i actually think what science is and this little little bit of what economics is or should be is about plausible storytelling. It's a convincing story that the bits connect in ways that human beings think are convincing. But without fairies. No fairies. I don't agree with that. You're one of the hosts, you're not allowed to do that. No, but the reason being that if you look at physics,

which is my area, then really I would say that the science, the toolkit as Ben described it, really the aim is to remove the human from the story. I mean, what we're really trying to do, I would say, certainly in physics, is to observe nature in an objective way and try to build theories. But that's your science. What about all the other sciences?

Well, there are. He doesn't think there are. Exactly. You've just described one science, physics. But, I mean, you can have a scientific approach to things, even where human beings are, you know. Economics is an interesting area in that respect, isn't it? Because it is inextricably bound up with politics, which seems to be inextricably... No, look, I'll tell you what.

The problem with economists and economics is rather special. It's that, unlike physics, which is for wimps, where you carry out a test... That's a weakly interacting massive particle. That's what you're trying to do. The candidate for dark matter. You carry out an experiment,

and it will give you more or less the same results each time. Why is that wimpy because you can it's possible to kind of get results and where you know what the variables you're investigating are the thing about economics and this gets right back to why the human element is not going to be removed the thing about economics is there are lots and lots of variables not only there are lots of variables you don't even know what the variables are. So you take something like a theory in economics, trickle-down economics, okay? The theory that if the rich get richer, it trickles down and the poor get richer. Is that true or is that not true? Well, I could cite China. It has been pretty true in China over the last few years. Or I could cite

the United States. It hasn't been true in the United States over the last years. There are so many variables. So as soon as you've got a theory or a phenomenon that you're trying to explore and you haven't got a test which you can repeat, you haven't got five billion pounds in a big tunnel under the Alps and a million computers. When you haven't got all of those things, you suddenly have to use some judgment about which variables are driving it in China, but not in the United States. And you need people of all kinds and all types to throw in their thoughtful views

about what might make a difference between China and the United States. It seems to me that you're describing a subject that has absolutely no content at all, because there's absolutely no correlation between your actions and the outcomes. No, no, but it would be mad to say that there isn't something going on in China, interesting, and that there isn't something interesting going on in the United States. And I think it's interesting to ask, and I think as important as any other question we will discuss this evening, what's going on, why is it different, why some places does it trickle down and not in other places?

So is any of it to do with economics at all? You're essentially saying that you've got an economic system mixed in with a social system and mixed in with natural resources in the country, etc. You put the labels on it. It's just one big, bloody complicated system, and you're trying to work out what is the active ingredient without knowing what the active ingredient is,

or even knowing what the ingredients are. It could be a million different things. Completely useless area. No, it's quite interesting. And it does get us somewhere. I mean, you know, let's face it, it has had one or two public relations disasters in recent years, but it has got us somewhere. I mean, you know, let's face it, it has had one or two public relations disasters in recent years, but it has got us somewhere.

You know, it's not utterly useless. It's got us in quite a good place. Ben, is economics useless? Well... No, I'm sorry. I'm sorry. Comment how you would like to comment. Look, I think something really interesting and important

and dangerous happens when you try to use the tools of science to explore an area where your results are often different depending on the methodological approach that you take or just simply because of the noise in the data. Exactly. And that's firstly because if there are lots of legitimate arguments to be had about the precise methodology that you should use to analyse your data, then there's room for people to be prejudiced in their choice of methodological strategy.

And actually there's quite good evidence showing that people will pick holes in the methodology of research which gives answers they don't like, but accept weaker forms of evidence for things that they already have a prejudice to believe in. So they're picking the methodology. We even pick our data to get the results we want. Exactly. But also I think there's something else very dangerous that happens, which is when we're dealing with systems like patients or the economy, there's a lot of noise in the data, and so every time you do exactly the same set of observations,

even in the same system, let alone different countries or different patients in different parts of the country or the world, you'll get slightly different answers. And that acts as a cloak that protects people engaged in bad behavior. So you get much more fraud in medicine, for example, than you do in physics. Because if you fake the results of an experiment in physics, well, the next person who does it doesn't get the same results as you, and then you're pretty rapidly found out. Whereas in a clinical trial, for example, there are so many extraneous variables affecting the main result that it's very common that trials have completely different results

in different populations, or even in the same population, but at different times. And so you can get away with being a fraudster in medicine better than anywhere else if you're looking for career advice. So when philosophers of science have tried to talk about what is a science, they've always kept to the easy stuff like physics and they've always stayed away from the difficult stuff like medicine. And in medicine there is a huge literature

on how bad we are as doctors at doing science even when we pretend to do science. Well, this is actually we should pick up on that, which is, I mean, in many ways, some people say it's really only in the 1970s that you properly see within things like general practitioners evidence really being used as opposed to a lot of it being anecdotal, just from doctor to doctor, and that's what we use. So I wonder if you can expand on that as well, which is quite shocking.

Yeah, it's extraordinary. So if you read the autobiography of Archie Cochrane, who is the great-grandfather of evidence-based medicine, he describes having stand-up rows with doctors, senior doctors, as late as the 1970s, who refused to do randomised trials to see whether their favourite intervention actually worked or didn't work. There are letters to The Lancet that describe evidence-based medicine fanatics, and I suppose I count myself as one,

as jumped-up, numerate, know-it-alls, trying to bamboozle their elders and betters. People viewed it as a challenge to authority. And people think of evidence-based medicine as being a force of nature, but it's actually a very, very new phenomenon. But just to not give any hints to the philosophers and sociologists of science who like to critique science, the best story about how we have failed to competently do evidence-based medicine in medicine, the best critique of how we fail to do science properly, actually comes from scientific research about scientific research. For example, there's a researcher called Stuart Greenberg who did an extraordinary paper on citation bias.

So he went out and he found all of the papers which suggested that beta amyloid protein was involved in inclusion body myositis. Yeah, I remember it well. And then he found about a dozen, and half of them said this protein is involved in this disease, and half of them said this protein isn't involved in this disease. And then he went and looked at all of the other papers

in the scientific literature that cited these basic lab science reports. And what he found was everybody cites the studies with the positive results, and almost everybody ignores the studies with the negative results. Even the people who did the studies which had the negative results ignore their own negative results. So it wasn't politics, it was belief.

And we create myths in science by doing bad science like that. And the extraordinary thing is that this is so prevalent and the medical establishment has proved itself so reluctant to address it that actually I think we have to start accepting that that is what evidence-based medicine is. Right now, evidence-based medicine really is people doing science badly. Sophie, in the area you're in, neuroscience,

again, we're talking about very recent changes in terms of the use of evidence, the understanding of what is good evidence. But in the human mind, where do we see the point where you could actually say this is now working as a science? I mean, we were talking earlier about the idea of mapping parts of the brain, which a while back people went, this is going to reveal so much, and now there's some people who are very harsh critics saying,

well, we see that bit light up, but do you know what? It doesn't tell us much of a story. I think that argument is missing the scope of where we are on this story if you look at where we are in terms of being able to look at the brain and how the how the human brain is working and not on a slice a living one all our brains now what they're doing we now have the techniques for doing this we've had that for 20 years if that we're in the early days we've just got our telescopes. You know, if you track it back to how long

people have been able to investigate heavenly bodies, we're sort of a comparable amount of time in. So you can trace the history back so you can see in the 1800s people doing really rather beautiful work looking at, you know, how brains were working. People started to be able to look microscopically at the brain

and to do surgery and see what would change following, you know, like some beautiful stuff mapping motor cortex in dogs, for example. So we've had good ideas from that, but it really took these new techniques like fMRI and EEG and these other sorts of ways of looking at healthy brains working to be able to start to unpack the whole normal system. And we are in the foothills. There are ups and there are downs.

So I think it's encouraging to me that we have debates around it because it means we've not reached the stage where we're just going, ooh, there are blobs in the brain. That's got true written all over it. That's good. We don't want to be thinking like that because it's a science and that's not how science works. So we should be being critical of it and we should be asking important questions of it and holding it to a high standard of evidence

but we should definitely carry on doing it because we've literally only just started Evan I wonder whether one of the problems sometimes perhaps with with some areas of science is because it is looking for the least wrong answers not necessarily the right answers that we do end up in a world where people will go well I've also got another wrong answer which is as good and someone wrote to me a while back and they said if science is so good why do they keep having to change it and then he said they haven't even worked out how the universe began and I kind of wrote back to him I said well they've got to kind of roughly the first 10 to the minus 34th of a second but there's work to be done and he said well that means that my idea about how the universe began must be as good and then i had

to try and explain that there's different levels of wrong and i wonder if that that is well that's the storytelling again isn't it it's about it's a brian's story about the start of the universe the big bang is more convincing than the one that went you know 500 years ago about it sitting on the back of a tortoise or whatever so it's um is about stories, and it's about the robustness of those stories, and it's about the way in which the stories supplant each other. So I come up with my story, and then you pick a hole in it, and by a process of picking holes, we get a better story. Do you think science is, given the...

I was going to say the respect it deserves, but given it allowed to have the influence it deserves to have, thinking particularly in politics, we see controversy all the time regarding scientific advisers, scientific advice to MPs. Do we see that when the advisers all agree, though? You know, you look at something like the advice to pregnant women as to what they can eat, which is basically nothing.

And... Let me just say, we're not advising you to eat nothing. So you look at that and you say... I mean, a politician, some poor sucker up in Whitehall, has to actually make a decision about what the official advice is or what policy is towards pregnant women so I suppose are there cases where they really ignore the scientists where the scientists are a hundred percent clear because I think there's quite a lot of respect for

scientists uh but well there are many issues we come to Ben in a moment but are you going to say scientists is that where you're going to say badgers no uh well badgers are one but i mean i think often people try and use disputes or apparent disputes about scientific evidence as a cloak for their prejudices and the obvious one here is drug policy so when david nutt in what we now have to call the nutsack affair um When the government's scientific advisor on drug policy said, look, actually, MDMA isn't particularly more dangerous than horse riding, and cannabis is certainly nothing like as dangerous as alcohol, it would have been nice to see politicians say,

look, I understand that, and I understand that keeping all drugs illegal doesn't actually reduce the number of people using them but I just think regardless of the real world impact I just want drugs to be illegal I just feel morally it's just nice that the country sends out a message just says this stuff is wrong and actually I don't care if the impact of that is to increase the total amount of harm but you see the politicians in that case that's a really interesting one because I can see both sides of the argument of that is to increase the total amount of harm. But you see, the politicians in that case, that's a really interesting one,

because I can see both sides of the argument on that one. So I will, just for the sake of argument, absolutely, because I work for the BBC, I have no views or opinions at all. But just for the sake of argument, I mean, it might be that the politicians thought, yeah, OK, taking ecstasy, riding a horse. The scientists tell me that taking ecstasy is safer.

But when you look at people who ride horses, they meet nice people to get married to, they get a bit of exercise, they go out, they don't graduate onto harder animals to ride. And you might, as a politician, you might, as a politician, you might say to yourself, well, actually, I just don't think it's right to

give people a signal that riding a horse is no more or less constructive than taking MDMA. So, I mean, I can see where the politicians were there. The point is, there is actually, we don't want to be, you know, we don't want to be the tyranny of common sense to make us all batty,

but equally, just occasionally, there is such a thing as common sense, and it actually is quite good. And the mad scientists who say, I'm being scientific about this, even though it defies common sense, and we had quite a few of them in economics, I can tell you, by the way,

very qualified scientific people, who said, I know it's not common sense, but it is science. And sometimes they get it wrong. So occasionally there is a little room for common sense, and maybe the politicians are the check on that. But, look, I agree. I don't think we should use, you know, 3% of scientists say X as an excuse for not doing Y,

because, you know, if the scientists mostly agree... Government's also oddly reluctant to use basic tools like, for example, randomised controlled trials to find out which policies work best. So which method of teaching reading works best? Which... What kind of sentences are best to prevent re-offending amongst drug users? Should we have compulsory drug

treatment? Should we send people to prison? Which has the best long-term outcomes in terms of repeat offending, if that's the outcome that we're interested in? Capital punishment is really... No, capital punishment is definitively the best on that outcome measure. So, and I think that... Common sense. So, you have to set the moral constraints

on which interventions you're willing to use, but once you've decided, then it's a very simple matter of experimentation to find out which intervention is the best at achieving your stated outcome, which most people would say with recreational drug users who steal stuff is that they stop using the drugs and stop stealing stuff.

And I wonder if politicians are reluctant to use those tools because they're reluctant to have objective clear final definitive answers because they'd rather leave room for speculation sophie i know you i mean i think exactly on those lines i think it also kind of colors what you consider to be an appropriate scientific question so um i went to an amazing talk a couple of years ago by somebody at Surrey University, and she works. She's been doing research into young offenders, so young men committing crimes, and just doing an investigation of their levels of communication disorders, so measurable problems they have with language,

which is running at something like 80%. And that's not treated as a clinical problem in these boys because it's picked up after they're 11 if you get you've got a communication disorder have it picked up when you're at primary school because then it gets treated as a disorder once you're over 11 it's you're considered to be a criminal it's a behavioral problem and it's fascinating we really should know about this we should be doing something about this and nobody wants to fund it because it's not it's not a medical problem it's causing boring problems of crime and you sort of think well maybe we should know a little bit more about what we could do about this but because it's constructed as a criminal disorder

and behavior in that context then it's not it no it's not falling into anybody's remit for funding and nobody's actually doing the research into it we just don't have a we're not we're not pressuring for this to be done we don't consider it to be a scientific problem. Can I ask you actually... Sorry, Ben, go on. I mean, that's a really interesting example of where policy and science come to a head and also judgment. I mean, you wouldn't for one moment say science tells you what to do with antisocial 14-year-olds,

but you would say science can tell you a lot about what makes antisocial 14-year-olds, how to try and make fewer antisocial 14-year-olds, how to try and make fewer antisocial 14-year-olds, and it can tell you a lot about what will make antisocial 14-year-olds more or less likely to continue being antisocial by the time they're 18. But science won't tell you, what do you do? It'll just give you evidence that can be used to inform the decisions that you make. It seems to me that this may be wrong, you can challenge this,

but it seems to me there's a consensus here on the panel, at least, that if you can apply the scientific toolkit to a problem, then that is the best way of proceeding. It is a desirable thing to do. But maybe you can't because the problem is too complicated or you're not phrasing the question in the right way. That, though, is a statement that sometimes, I think,

rubs people up the wrong way because what you're essentially saying is that the scientific way of looking at the world is superior to the other ways. If you can do it, if you can apply it, then that's what you should do and the mess and the opinion comes when you just can't apply

it for one reason or another. Well, the mess and the opinion comes when the problem is too complicated. You've got too little data. You've got fewer data than... You've got fewer observations than potential variables affecting. It affects you things you know about. Is this degrees of freedom in equations? If you've got five things that may be driving something and you've only got four data points,

you cannot possibly work out which one of those things is driving it. Do you think that's accepted, though? Because on the Today programme, you have all sorts of people and politicians and interest groups, and you have discussions every day. Do you think it's generally accepted that if this scientific toolkit can be applied to a problem, that is the most desirable thing to do? Well, yes, I do. do i mean i think if you

if you say we'd rather have people who are objective rather than subjective subject to my rider that sometimes you need people to apply judgment and that's going to sometimes be left wing or right wing or reductionist or complex but yeah no i think you you absolutely what was the question again so that's usually Robin that goes, that's that. So do you think that we live in a world that, in general, respects science and the scientific method? Yeah, objective is better than partial. Rooted in experimentation or in data is better than not.

Simple theories are better than complicated theories if they have the same explanatory power. All those kind of scientific precepts in the toolkit, better than not. We've won the argument that we should do that. Everybody likes to pretend that they engage in evidence-informed policy. At least nobody ever says, hey, I'm just going to go massively against all of the evidence right now. Nobody ever says that.

And so now that everybody is at least aspiring to have respect for good quality objective evidence about what's going on and what action is likely to have the best outcome, we're now, I think, allowed to start having an argument about whether they're doing it properly or not. And a lot of people do it very, very badly in policy world in particular, but also, I think, in economics. One thing that we were originally, when we started talking about this, and we've talked in lots of interesting areas, but about what makes a science a science, and I wanted to go to Sophie for you on the practical side. Early on, we were talking about, before the show, Richard Feynman, the Nobel Prize winning physicist,

and he once came up with a problem-solving algorithm. And the problem-solving algorithm was, number one, write down the problem. Number two, think very hard. Number three, write down the answer. Now... I did want to just go back this... Number two, think very hard. Number three, write down the answer. Now... I did want to just go back.

I know it's going back a long way now from where we started, but, for instance, when you look at an idea, when you are starting to deal with an idea of the mind, an idea of neuroscience, can you just run through the actual process, the practical process of what you do? I suppose what the first question is, you know, to say something I'm interested in.

So one that I am interested in, laughter. It's an interesting behaviour. So say I want to say, what's actually happening? If you've got a lot of people laughing, how do they laugh together? They all start at the same time, then they all... We coordinate lots of behaviour. If Ben and I were to get up and walk around the room together, we would fall into step.

What would Freud have said? So right now, when you're laughing, is that sort of thing happening? And so we've been trying to sort of find ways, natural environments, or get into comedy gigs and look what's happening to the audience and spoil comedy for everybody, or get people into the lab. So the question is, if that's one of the things I want to know about laughter, then I'm going to have to go away from the brain and start looking at people interacting.

And other questions, it's going to make sense to talk about what's happening in the brain. It depends. It's not like you've got a method and then you just go and apply it like a hammer to nails and you know to all your things that strike you as an interesting question i think one of the things i like about psychology and cognitive neuroscience is it gives you a range of things i can use transcranial magnetic stimulation or i can use near infrared spectroscopy or i can just do a reaction time. It will all tell me something

that could be relevant to what I want to know. So it's like you've got a palette of these tools at your availability. I wonder, Evan, what you might think in terms of... Again, before the show, we were talking about what couldn't be dealt with scientifically. I know something Brian, you always talk about, which is if you can use evidence, if you can use evidence to make a decision,

then you should use evidence. But where do we find... You were mentioning with economics, the problem is we're dealing with human behaviour and we're still quite confused as to how we work. Yeah, that is the problem. The problem is where the problem is complicated and where you don't know what's driving it.

So there you need to apply a theory or you apply an external account of what is going on. Or do a randomised trial, which was what... Well, you may not have a randomised trial of a country over 100 years. So I'll tell you what, one very interesting area where science struggles is the long term, isn't it? I mean, the long-term changes in planetary conditions

are quite difficult to experiment with. We're running, what, you know, quantitative easing at the moment. Paul Krugman has lots of views. He's an American economist, Nobel Prize winner, brilliant guy, very cocky, very sure of himself. He's absolutely sure that austerity is failing. He's looked at the results of austerity and says it is failing. I was right to say it was going to fail.

But we don't really know what, in ten years' time, would have been the outcome of the alternative or what the alternative would have been now. In the absence of counterfactuals, in the absence of knowing what the variables are, in the existence of a long term, which is way beyond the kind of experimental period... Ben's trying to

come in but i'm just gonna and and incidentally one other case which makes it very difficult where when you start looking at a variable this is again brian you don't have this in physics when you start looking at a variable in physics it doesn't suddenly start misbehaving in economics you start looking at something money supply m3 you say we're going to look at M3, then suddenly the banks change their behaviour and so M3 no longer does what it was doing before. So there are loads and loads of areas where life is very difficult if you want to apply those scientific tools

without using some human judgement on top. To be fair, physics does, though. Particles do misbehave. Once you stop observing them, they get up to all manner of shenanigans. Ben. Well, this is a council of despair, and we shouldn't use it to allow ourselves off the hook of at least trying to use good evidence.

So in a complex system, you may not be able to explain all of the variation, but you will be able to explain some of it, perhaps, and so you should do your best. So, for example, I can tell you from having done talks in lots and lots of different rooms that sometimes people laugh at exactly the same talk and sometimes they don't and i i can't explain all of that variation but i can tell

you that if you show up somewhere to give a talk and it's a massive gymnasium with some stacked chairs in the middle and the room is basically a third full and there's lots of dead space and nobody's sitting very near anybody else, then they're just not going to laugh. There are certain room designs where you know people aren't going to laugh. I can actually tell you why that is, but maybe that's too far.

No, go on. This is a science show. So I can't tell you everything about why people do or don't laugh on a particular night, but I can tell you something and try and modify that and try to address it. So we'll agree that there are more intelligent and less intelligent ways of approaching these difficult problems. And it's not intelligent to evoke the fairies or to just take wild stabs. It's just a little bit of caution about believing that you can make a simple physics problem out of a complicated human problem. I think we are going to have to draw a line now.

The one relief is definitely, even after this hour, Brian, physics remains a science, which I know you were worried about at the beginning. Well, no, I'm heartened that actually that just seemed to be accepted and taken as well. And we've got into discussions about all that squishy nonsense to do with humans, but actually the study of nature remains a science.

At least we've all agreed on that. Good night. We've got... No, we have actually... There's more. We did ask the audience a question. We always ask our audience a question. What was the question? The question was, what do you want scientific proof of? What do you want scientific proof of?

The evolutionary advantage of itchiness. Intriguing. Oh, this is a good one. The melancholy gene exhibited by goths and poets. What do you want scientific proof of? The thoughts of horses. With an

exclamation mark there, suggesting this was by someone who's just recently seen Equus. Well, I just wanted to say very quickly, so you were discussing this very... Yeah, I was looking at a very good student project this week from Sussex where they were looking at emotional expression in horses as perceived by horses. So showing horses photographs of horses in happy moods,

which is ears pointing forward, or horses in neutral moods, which is kind of going sideways, and horses in bad moods, with his ears pointing forward, or horses in neutral moods, which is kind of going sideways, and horses in bad moods, like that. And it's just fantastic photographs of horses, happy, sad. Horses looking at these. So, yes, they're thinking. So that one, at least, has been done.

What do you want to sign in for proof of? The person sitting next to me really is my son. Whoa! Steve Williams. I want scientific proof that things can only get better. No! And finally, that the person sitting next to me is my dad. That's Richard Williams.

Thank you very much for all of those answers. There were many more as well. Thanks to our guests, Professor Sophie Scott, Dr Ben Goldacre and Evan Davis. Goodbye. Goodbye. If you've enjoyed this programme, you might like to try other Radio 4 podcasts, including Start the Week, lively discussions chaired by Andrew Marr, and a weekly highlight from Radio 4's evening arts programme, Front Row.

To find out more, visit bbc.co.uk slash radio4. In our new podcast, Nature Answers, rural stories from a changing planet, we are traveling with you to Uganda and Ghana to meet the people on the front lines of climate change. We will share stories of how they are thriving using lessons learned from nature. And good news, it is working. from nature. And good news, it is working. Learn more by listening to Nature Answers wherever you get your podcasts.