Intro. [Recording date: December 4, 2025.]
Russ Roberts: Today is December 4th, 2025, and my guest is psychologist and author, Gerd Gigerenzer, of the Max Planck Institute for Human Development. This is Gerd’s third appearance on the program. He was last here in August of 2022, discussing artificial intelligence.
Our topic for today is his book, The Intelligence of Intuition. Gerd, welcome back to EconTalk.
Gerd Gigerenzer: Oh, I’m glad to be here with you again.
1:04
Russ Roberts: Tell us what you mean by intuition. It’s a very imprecise word to some extent, but you mean something a little more precise.
Gerd Gigerenzer: True. Intuition is a feeling based on years of experience that comes fast into your consciousness–so, you feel what you should do or what you shouldn’t do–and where you have no way to explain it, where it’s coming from.
So, it is not an arbitrary decision. It is not a seventh or sixth sense–depending on how you count the senses.
And, it’s also not something that only women have. So, everyone has intuition who has experience with a certain domain or a task.
Russ Roberts: So, you mention women. The first part of your book is an intellectual history of how intuition was treated as a woman’s expertise as opposed to, say, rationality or reason or analytical ability. And, that this did, of course, a terrible disservice to women and to our understanding of rationality and intuition.
Gerd Gigerenzer: That is true. So, into the 20th century, textbooks in psychology were promoting the idea that men’s intellect is very different from female’s intellect. And of course: We men are rational, with reason; while women are intuitive. And an entire dichotomy was there. So, intuitive versus rational, associative versus deliberate. And also, fast. Women were thinking fast. That meant not reliable. We were slow. And, at the end, if women did something wrong, in many societies they were not responsible, but the husband was responsible.
And, interestingly, this dichotomy turned, now in the 21st century, a distinction between a System 1 and a System 2. System 1 was the idea about women, System 2 about men. And, to the point that all kind of errors–including the difference between the research of Kahneman and Tversky, who showed that mostly people err, and my research, who show that in the same task, people get it right–was then reinterpreted by Kahneman. And he says that was his solution to our debate, in the terms of System 1 and System 2. So, if you do something wrong, it was your System 1. If it is right, it was your System 2. And, even to the point that System 2 has to pay attention [?to?] System 1 [inaudible 00:04:28] correct.
4:29
Russ Roberts: You’ve been defending intuition for quite some time. And, I suspect during some of that, it was a little bit lonely. I feel like intuition is having a comeback or its day in the sun. I interviewed David Bessis recently on his book, Mathematica, which–he really champions intuition. He relates it to System 1 of Kahneman and Tversky, but he says there’s System 1, which is vision, which helps you see something you wouldn’t otherwise see, and insight. And, it’s visual. System 2 is analytical and you use System 3: You combine the two to figure out sometimes your vision is wrong, so you check it with System 2, but often it’s right. And, if it’s wrong, he talks about using, quote, “System 3” to figure out what you need to learn, so that the next time you see something–a vision, say, in a mathematical proof or science, that you have a better track record going forward.
And then I interviewed Angus Fletcher recently. His book, Primal Intelligence, is very much a defense of intuition. Slightly different interpretation than yours, but in the ballpark. And, I’m curious if I’m right that your feeling about how the world looks at your ideas has changed recently, or is it no different than it’s always been? I feel like there’s a newfound respect for intuition and that your work is going to be respected more than it has been in the past. Am I right?
Gerd Gigerenzer: I think you’re right. Yeah. So, I wrote a book called Gut Feelings, long time ago. And, a few years later, Malcolm–what is his name?
Russ Roberts: Gladwell.
Gerd Gigerenzer: Gladwell–yeah, sorry–wrote a book where he took up some of my ideas, in Blink, and popularized it. And, I think that more and more people are coming clear or being clear that without intuition, we would go nowhere. There would be no innovation. And that the war against intuition is totally flawed.
And, I just add one thing: There is no opposition between intuition and conscious thinking. That’s the big mistake of the System 1 or System 2.
Just to give an example, a doctor that knows you well, Russ, and today the doctor thinks something is wrong with you, but the doctor cannot explain her feeling. That is intuition. Based on long year experience, the feeling is there immediately; but the doctor cannot explain it. Now, what does a doctor do? No? Diagnostics. So, that’s totally deliberate. So, in that example, the intuition inspired the diagnostic. Without intuition, there would be probably no diagnostics. So, there is no contradiction there.
8:02
Russ Roberts: Yeah. I love the quote you opened the book with: “We know more than we can tell.” Which I think is Michael Polanyi.
And, I have a different translation on the Pascal quote you like. I like to say, ‘The heart has its reasons that reason does not know.’
Our culture mocks that, right? Our culture: ‘Well, if you can’t explain it, if you can’t justify it, you can’t tell me, I’m not going to pay any attention to it, because it’s not rational.’ And, it’s a misunderstanding, I think, of what rational is.
And, I don’t want to miss this chance. I said the world is coming [?]toward[?] in your direction, but it’s also the case that it’s running away. And where it’s running away is in the discussion of artificial intelligence, which we talked about the last time; and I want to revisit some of that.
There is definitely a belief among many, many people in the field that artificial intelligence–which is very much not intuitive, on the surface at least–is going to solve all our problems. It’s going to know things that we can’t know, because we don’t have enough bandwidth and our memory is not like theirs, of artificial intelligence. And I think it’s a fundamental misunderstanding of what intelligence is, at least at its current level. And, do you agree with that?
Gerd Gigerenzer: Yeah. So, there’s no method or no technology that can solve all problems. That’s a religious faith. It’s like God. Please, God, help me to solve all my problems and I believe in you. And, we just should step back and think about the technologies before that we believed might solve everything.
So, we had the human genome project. Remember that?
Russ Roberts: Yeah.
Gerd Gigerenzer: And, people thought that if we know our entire genome, we can cure cancer, we can cure Alzheimer. We know everything about us. It’s much more complicated. And, it’s the same with AI [artificial intelligence]. And, by the way, those abilities that we have, which are highly unconscious and intuitive, are often the hardest for AI to do. For instance, watch the world soccer champions in Robot Soccer. It’s a comedy; and then you can see how difficult it is for a robot to understand what’s going on in a soccer play.
So, we are far away. There are certain things where AI is better than humans, and that’s often well-defined worlds like chess and Go, or industry applications, or large language models which work on a corpus of words and the correlations that doesn’t change. So, these types are easy for artificial intelligence. But the moment there is uncertainty, you have to predict the future, it gets difficult. And predictive AI, particularly if it’s about humans or about viruses, there’s little success.
Russ Roberts: But the people in that field, I think overwhelmingly–and there is a religious aspect to it; I’ve referred to it a number of times–but I think they feel very strongly that, well, that’s today. Twenty years ago, you said AI would be–not you, but the world–said AI will never solve Go–the game of Go. And, it did. It’s very good at it. ‘It’ll never solve chess: there’s too many combinations.’ It’s really good at chess. And you say: But those are worlds that are well contained. They have specific rules, those worlds. But it might cure cancer. That would be great. I’d be thrilled if it could cure cancer. It is more complicated than it appears on the surface.
The part I have trouble with is: ‘It will cure poverty,’ as if poverty is a technical problem that we just–we know what the solution is, but we just can’t implement it or we can’t figure it out. ‘But it will. It will know how to do it.’ And I think that is unlikely. I’m very skeptical about those kind of social problems. Or fix democracy, to be even more absurd.
Gerd Gigerenzer: It seems rather, if anything, the opposite. So, the difference between the poor and the ultra-rich are getting larger. For instance, compared to last year, there was just a report that the billionaires are getting richer and richer and richer, particularly the tech billionaires. And, just another example, I mean, the energy–the need for energy of the big tech companies have that is going totally against taking care of climate change and something like that.
Russ Roberts: ‘But then it’ll figure it out. Give it time.’ All I meant to stress was that there’s a techno-optimism, I think, that is relentless. And so, when you say things like, ‘It won’t solve this problem, that problem,’ I think the standard response–and it might be right, of course–is, ‘Well, it will just take longer than you think. It’s just a matter of time.’ I think there are many human problems that are not of that nature. And, the idea that somehow we haven’t solved them because, quote, ‘We aren’t smart enough, but a smarter machine will,’ I think is a misunderstanding of how the world works. But maybe I’m wrong.
Gerd Gigerenzer: Yeah, it’s a common rhetoric. But just take the example of the human genome project again. We had the same rhetoric: ‘Just wait until we have [?] all the genes, and all of these, we will cure cancer.’ The problem is that there is so much interaction between genes. There are so many genes which are out of business for some time, and things are not as easy.
And, if you look behind why these claims have been made about AI for the last 50 years–overstatements–is in part because of funding. Getting funding from science, getting funding from politicians: Tell the politicians stories that they believe, because they don’t read. And so, you get the money and then you don’t care. And, declare everyone who doesn’t believe your face[?faith?] is anti-technological.
It’s the opposite. I mean, the big successes are done by basic fundamental research. Without a Max Planck or an Einstein, there will be no lasers. Very little of this technology that’s being used today. But, these people are doing promises in order to get their own stories through.
15:51
Russ Roberts: I just want to add one more thing about AI. I think I’m right on this, but you can correct me or a listener can correct me. So, I sometimes ask AI to write a biography of me. I’ll ask one of the–I subscribe to three or four, because I think it’s important to understand, and I enjoy it, too. It’s fun. I get amazing use out of it. So, I’m not against it in any way. So, sometimes I’ll ask it to write a biography of me, because I know I’m pretty good at checking whether it’s hallucinating or not. And, the last time I did that, it gave me a Chair in an Economics Department at a university I’ve never taught at–and never had a Chair there either, by the way. And, I thought, ‘Well, that’s interesting.’
And, now in the new world, they give you the source sometimes. And, so, I click through, and there is a website that has falsely attributed a Chair to me that it decided was deserved.
And, what’s weird about AI, at least as I understand it right now, is I can say to it, ‘Oh, by the way, Russ Roberts doesn’t have a Chair at that university.’ And, it goes, ‘Oh, I’m so sorry. Of course it doesn’t.’
Sometimes it does that because it literally made it up.
But, either way, when you ask for a biography of Russ Roberts two weeks later, it could make that same mistake again, because it does not learn. It does not say, ‘Oh, I’ve got to correct that cell in the database now about what he did between 1977 and 1982.’ It just starts from scratch again.
And so, I find it interesting that it has no intuition in the way you said about it. It comes from a long experience. We as human beings, we see certain patterns that we unconsciously come to trust, and you see in a person’s face that they’re troubled, or the doctor sees you’re not feeling well and they can’t explain what it is sometimes, as you point out. But, if AI doesn’t correct its errors and learn that way, it seems its ability to access that kind of human reasoning is lost.
Gerd Gigerenzer: Yeah. One should not confuse deep artificial neural networks–that’s what it is–with human intelligence. That’s the old danger. It is something different that can do some things better than we, and we should use it for that. But, we should not fall prey to this religious faith that it can do everything.
There’s such a desire among humans to have a God, and only one God, who takes care and gives us certainty. Instead of: Science will develop. And I would bet in 10, 20 years, there will be a totally different kind of AI than this artificial neural-networks type.
Russ Roberts: Very possible.
19:04
Russ Roberts: Let’s shift gears. I love this part of the book. What is the ‘bias bias’? And, it’s a critique of an enormous industry, Gerd. There’s an immense number of books that come my way and studies that come your way on this topic that you are critical of. So, what is the bias bias?
Gerd Gigerenzer: The ‘bias’ bias is the misunderstanding–I’ll put it this way–the bias bias is the temptation to see biases everywhere, even if there are none.
And that is mostly due to researchers, but also to many people who want to use this to justify their policies, like nudging, political paternalism, and artificial intelligence paternalism. The argument is people have all these biases. Machines can do better. What do you want? Believe in machines.
And, what we know today is that most of the biases that are presented in the literature in these books that you talk about–like overconfidence, the hot hand fallacy, conjunction error, base rate error–
Russ Roberts: Framing–
Gerd Gigerenzer: Yeah–and framing are no biases at all. They may be bias in a certain situation, but not in others.
Or even worse in the case of the hot hand fallacy. So, that’s the claim that coaches and basketball fans make errors, because they believe that the player gets hot for some time. And then, allegedly researchers have shown that there is no hot hand. Now we know from a great article in Econometrica by Miller and Sanjurjo that it’s not that the coaches have a problem with statistical thinking. It’s the researchers, who didn’t understand that the properties of a sample are not always the same as the population.
So, I don’t want to go into detail. I’ve written in this book: you find many examples about the bias bias. And, in general, anything like overconfidence is good in some situation and bad in others. It’s not generally wrong. And base rate neglect is the best thing you can do if your world is changing quickly, but not good if it’s fractured. You need to think about this. There’s what I call ecological rationality, not just logic, but it has been used and misused for blaming people instead of blaming researchers, and social scientists kind of lose statistical thinking.
Russ Roberts: Yeah. We had a very nice episode with Ben Cohen on his book, The Hot Hand. And, I want to say one thing about the hot hand, which: it’s not an easy thing to measure or test, and people do write about it as if it’s just a question of making a few calculations. And, your point is that finally someone made an insight that actually sometimes you’re making the wrong calculation.
But, I think what struck me about that debate is that the size of the hot hand–even in the corrected study that found there actually is a hot hand–was quite small. Tiny, actually. And, I think if you ask Steph Curry or other great athletes about the hot hand, they would really laugh at the researchers. Now, that doesn’t mean anything. Obviously, people in a field can misunderstand what they’re good at, how good they are at it. But I am a little surprised at how small it is.
So, if it does exist, at least in the data, it’s relatively small. But, as you point out in the book–which I love, for a number of reasons, as listeners will appreciate–Gary Becker pointed out to you one time, you mentioned that when a guy is hitting shot after shot, you change your defense. You change who covers them in the basketball game. So, it’s increasingly complicated.
24:09
Russ Roberts: But, when I mentioned earlier that your work wasn’t so popular, because you’re skeptical about reason or rationality, I suspect that a person who calls something the bias bias, who likes to point out that the researchers have more of a problem than the decision-makers, I assume that it doesn’t lead to getting invited to a lot of the right cocktail parties and conferences. Am I right?
Gerd Gigerenzer: Depending on how you think. I think that it could be equally a topic of cocktail parties to just start thinking at cocktail parties.
So, for instance, take framing. So, a famous example is, so you have a severe heart problem and your doctor tells you–you consider a major surgery and you want to know the prospect. And, your doctor can tell you either you have a 90% chance you will survive or you have a 10% chance that you die. According to the framing literature, you should not listen to your doctor, because it’s logically the same.
Now, this is the opposite of psychology. We know from experiments by Craig McKenzie, for instance, and others, that people convey recommendations. And, if the doctor says you have a 90% chance to survive, that means: Do it. If the doctor says 10% chance you die: That’s a warning, not a recommendation, because the doctor knows more about that.
And now–and human are intelligent enough to understand. They can read between the lines. And that’s mistaken as a framing bias. Just think about that.
Russ Roberts: Well, I’m sure you remember the case of the–I don’t remember the researcher; people can look it up–but this person who got enormous number of citations in a psychology test of using words related to aging and being old. And, that was not the real experiment; but they used that, had them do the experiment. But the real experiment was how quickly the people left the room. So, the claim was is that after you heard words like ‘Florida,’ or–I forget what other words were relevant, but things related to seniors, supposedly–people left the room more slowly. That was the claim. And it did not replicate in a larger–it replicated. Many people found similar types of framing mattering. But, when it was done with a large enough sample, it wasn’t reliable.
Well, the original author–the author of the original study who had made the claim–one of his defenses was, is that people didn’t read the script correctly. Now, I have no idea how he knew that. It was kind of, I thought, a desperation claim to try to salvage his research.
But I’m just thinking about your recent example. If I’m in the doctor’s office and I say, ‘I don’t know, it’s major surgery. What are your thoughts?’ I mean, ‘How likely is it to succeed?’
If he says, ‘Well, 90% of the people survive. It’s pretty good.’ Versus, ‘Well, about 10% of the people die on the operating table.’
And, if you read the words in the writeup of this experiment that was done, obviously the intonation is not irrelevant. If it’s spoken, people convey enormous amounts of information between the lines.
Gerd Gigerenzer: Yeah. And, if you’re a doctor in the United States, then you fear being sued. You better be not to be explicit.
Russ Roberts: Yeah. Well, that’s another–yeah.
28:24
Russ Roberts: What’s the difference between boosting and nudging? And, speaking of trends, there was a period I felt where nudging was very in vogue. I don’t care as much about it as I used to. I’m not sure whether that’s just random or not; but you’re a bigger fan of boosting over nudging. So, talk about why nudging bothers you. A lot of people think it’s great. And, what’s boosting, and what’s the difference?
Gerd Gigerenzer: Okay. So, the term ‘nudging’ is from Thaler and Sunstein’s book, Nudge, and it’s based on the research of Kahneman and Tversky. To make it very simple, the argument is: People do not know how to deal with risks. Second, they cannot learn. The biasing doesn’t work. And, third, therefore, because that has immense consequences for our lives, government needs to step in and nudge people towards the direction where there would be anyhow, if they could reason rationally. So, that’s basically–it’s a justification for paternalism in the 21st century.
So, my research has shown, yes, people often don’t understand risk. If you present them in a way that have never learned, like conditional probabilities. If you present them in frequencies, they understand. Okay?
On the second assumption that people cannot learn, the evidence is totally different. We can teach. Already now made it with second class–so, seven- to eight-year-olds can understand Bayesian thinking, if you present the information in an intuitive way. And we’ve shown that with children in Germany, with children in China.
And on the third issue, so that you want to deal with people not by educating them–because they allegedly, there’s no hope–but by nudging them, I think that is, for me, an anti-democratic move. Democracy works only if people understand and are willing to take their part. And, if we want to have a new autocracy of a few decision masters that tell us what to do, where do we get? And, this is a similar movement towards replacing, no longer betting into people and making people strong, but replacing them by some algorithm or by some politically actor.
So, from my own research, the term ‘boosting’ came out. Ralph Hertwig has formalized that, one of my former postdocs. And, boosting means that you make people strong. You don’t nudge them like sheep. You make them strong; and they can start already in schools, make them risk literacy. And that should continue in journalism rather than going and, for instance, or in the parties that you mentioned here, cocktail parties: Rather than telling stupid stories about how dumb everyone else is and laugh, why don’t you tell a few stories how to understand things? How to understand what a positive test–you have a positive COVID [Coronavirus Disease] test. Does it mean that you have COVID? No. What’s the chance? Figure it out. So, useful things.
And, we know from when we teach children what it means. For instance, you hear in the weather report or online that there’s a 30% chance of rain tomorrow. What does it mean? Adults don’t know [?]. Some think it means–oh, so I live in Berlin. Most Berliners think it means that it will rain tomorrow in 30% of the time: that is, seven to eight hours. Others think it will rain tomorrow in 30% of the region, so ‘probably not where I live.’ And, the majority opinion in a study we did with a representative group in Spain, Spaniards think something different. A 30% chance of rain means that three meteorologists think it rains and seven not. What meteorologists really, really want to say is that given the constellation of today, it will rain in 30% of the days that are like tomorrow. So, most likely not.
Now, the point is: this example is very easy to understand. And, the general principle: always ask for the reference class. So, is this 30% about time or region or days or meteorologists? And, children by age 10 can easily understand that, and they can proudly go home and ask their daddy, ‘What do you mean it means a 30% chance of rain?’
And, that is part of boosting. And, it makes–its fun.
Russ Roberts: Yeah, it’s great.
Gerd Gigerenzer: And, it makes people strong and interested to learn something about the world rather than to be a mere consumer of the latest TikTok.
34:58
Russ Roberts: So, I’ve never thought about it, but ‘nudge’ is such a brilliant marketing term for this project, because it’s so modest: ‘I’m not going to shove you into one class or another or into some decision. I’m not going to even push you. I’m just going to give you just a nudge.’ Which sounds modest. You could call it ‘manipulate’ instead of ‘nudge.’
You give an amazing example in the book, which I’ve never heard. Yeah, I’m a big conserver[?] of this kind of stuff. And, like you, a famous example of nudging is opting in versus opting out.
So, if on your driver’s license, if you want to donate body organs if you were to be killed in a car accident, you have a choice. The state–the government–has a choice. They can either say, ‘Well, everybody has to donate their organs. But of course you’re free–because we believe in freedom–to opt out.’ So, you can choose to say, ‘I don’t want to do this.’ It will be on your driver’s license.
Versus: ‘Well, no one should have to give an organ without a free choice. So, if you’d like to donate one–this is opting in–you can choose to do so.
And so, one of the proofs of the power of nudge–whether it’s a good idea or not, and of course you in the book point out, we’ve talked about it many times in the past when it was a more contentious issue in public policy. Obviously the people who are designing the nudges are not saints. There’s political influence. I really don’t–these are[?] about democracy. I don’t think it’s good for democracy to give this power, even if it’s somewhat limited and there’s still freedom to influence people if it actually works.
But, this case: I mean, who doesn’t want more organs? We have a kidney shortage everywhere in the world, almost. So, please, the implication of this is that–excuse me–the finding on this–is that when you have people opt out–have to opt out–most people will just go along with it and they won’t opt out, versus opting in. Not so many opt in. So, the result is if you have opt-out, you get a lot more kidneys and a lot more other organs; and opting in is just feeble.
But, you point out it doesn’t work out that way, which is fascinating and obvious that I’m ashamed I never thought about it. Explain what’s going on there.
Gerd Gigerenzer: Okay. If everyone is an organ donor, except those who opt out, you have more organ donors than if it’s the other way around. Hm? Yeah.
But, you have only more potential organ donors. Potential. What you want are real organ donors; and there is much more to do than just having an opt-in or opt-out policy.
So, there are two studies out now. One has looked at 35 OECD [Organization for Economic Co-operation and Development] countries. About half of them have an opt-in, half of them have an opt-out policy, and have looked at the actual organ donations. Not the potential. The potentials are very different. And, the actual don’t–
Russ Roberts: Before you go on, when I first read this in your book, I thought, you mean you’re telling me that after the person gets killed in a car crash, they say, ‘I changed my mind?’
That’s a macabre, dark way of making this distinction, but that’s not what happens. Why is there a difference? Why should there be a difference in potential and actual? I mean, they’ve accepted it. It’s on the driver’s license.
Gerd Gigerenzer: Yeah. Just assume–or put it this way: So, if there’s a motor bike accident–which is a typical situation–and the person is dying. Now what you need, you need to get this person to a hospital and need to get this person to hospital in time. And the hospital needs to have a room prepared, and the personnel, and to make the operation, the surgery. And, they need to have this coordinated, so that the person who gets the organ is also there. So, there’s a huge body of organization being done.
And, moreover, the hospitals need to have financial incentives that they keep the surgery room and also this equipment in place. And, if you don’t have that, then potential organ donors don’t help you.
And, Spain is the country who has the best organization and has the highest number or proportion of actual organ donations. Spain had–began with the policy of opt-out, and it didn’t work. And, only when they started to organize the system so that it’s fast. And, for instance, the psychological part is not presenting the default, but talking with the parents or the relatives. Because, at the end, it’s not the opt-in or opt-out default, but it’s usually the relatives who decide.
And so, to make it short: the problem is much bigger than a default. And, the two big studies that have been out, the one, the OECD studies, and the second one done at the Max Planck Institute for Human Development, where I am, had looked at countries that actually switched from everyone is not a donor except the person opts in, to everyone is a donor except the person opts out, and have looked at what happens. The number of potential donors increases, yes; but the number of actual donors did not increase. And the reason is simple, because the system is not being changed.
41:52
Russ Roberts: It’s a fascinating example, because it’s a form of virtue signaling. Everybody feels good when the potential donor group goes up–the number of people who put this notation on this driver license when they sign up, say. And, it actually fools you into thinking you’ve done something.
And, your point is that actually that’s not the hard problem. The hard problem is getting the system mobilized to actually collect a kidney, not to get the agreement of the person. That’s much more productive rather than saying an advertising campaign on, say, getting people to opt in or out.
There’s an example you give in the book, which I think kind of highlights the political challenge, the democracy challenge, the paternalism, treating people like adults [?like children?–Econlib Ed], as opposed to treating people like adults.
And, it comes up with screening. And, we’ve had a number of people on the program talking about how so many, many medical tests and screenings are not as productive as you’d think, but counterproductive. They actually end up with more deaths, because of false positives. They create anxiety. And you quote a politician saying, quote: ‘We can’t show this to the public, these results that are discouraging. They would not have cancer screening anymore.’
Well, yeah.
And then, another example you give: a policymaker raised his hand and said–you were talking about boosting versus nudging. He said, ‘Well, why inform if we can persuade?’
Well, because you can make mistakes, and you can fool yourself into thinking you’re doing something that you’re not. And, it’s a nice example.
Gerd Gigerenzer: Yeah. We are back on the topic of paternalism.
Russ Roberts: Yeah.
Gerd Gigerenzer: Yeah. And, cancer screening is a good example, and in particular, mammography screening. So, I see women in different countries react very differently to it, but almost all are not informed about the scientific evidence. To make it short: If you ask, ‘Does mammography screening–and screening is for people who do not have any symptoms–does mammography screening prolong your life? And, if so, how long?’ The answer is from randomized studies, randomized trials, the best thing we have. And, the answer is mammography screening prolongs life by zero days. Zero.
Russ Roberts: And, that’s on average. Obviously–
Gerd Gigerenzer: Yeah, it’s always on average–
Russ Roberts: it would depend on what age you are when you get the screening, what the policy of the country is, what your personal history is. This is not a show about medical advice, but it’s illustrative of an important point. Carry on.
Gerd Gigerenzer: But, women are deceived into that. So, this information is not passed on. You find this in the last large review in JAMA [Journal of the American Medical Association], and women are told there’s a 20% reduction of breast cancer mortality, and that’s–
Russ Roberts: If they get a mammogram–
Gerd Gigerenzer: Yes. Yeah. And that’s a form of nudging. So here’s: you assume that women do not know the difference between a relative and absolute risk. So, you communicate that in relative risk, because it looks different, and, ha, they believe it’s a big effect.
So, the studies show that out of every thousand women age 50 and older who participate in screening, four die after about 10 years of breast cancer, and out of thousand who don’t participate, it’s five. So, there’s one in thousand, from five to four in thousand. That is 0.1%. That is not impressive, isn’t it? So, you communicate that effect as a 20% reduction instead of 0.0.
Russ Roberts: From five to four.
Gerd Gigerenzer: It’s [?] 20%. And then, that’s only half of the truth, because in the screening group, another[?] women dies from another cancer. This is why, at the end, there’s no difference. And that’s not communicated. And, for the reasons that you just mentioned, it would destroy a billion-dollar business. Rather, nudge women into screening.
Russ Roberts: But, there are many good-intentioned people, I think, who would argue–and I understand the argument and I sympathize with it, though I do not agree with it–which is: Better safe than sorry. It would be the argument. ‘It’s true, it’s a small change, but it’s still something.’ And, my view of it is it creates a lot of anxiety, the false positives that, you get into the clutches of the industry–and of the healthcare industry–and a set of tests go on and on and on. And, some people for peace of mind will always opt for more tests and more surgery, because they would rather be proactive than reactive. And, that’s part of the human condition also. So, I don’t want to minimize that, but–and we’ll link to some of the episodes we’ve done on this with Vinay Prasad and others.
Gerd Gigerenzer: Just to say this, given what’s communicated to women is one in 1,000 or 20%, it looks like there is something small. But, notice that what is withhold that there’s also one in 1,000 chance that by screening you die from another cancer. And so, there’s totally nothing to be gained. Only the harms, and we have not talked about the harms. And, if you are going to win the war against cancer, it is not screening. It is prevention. About half of all cancers are due to behavior, and we should start early. So, behavior is smoking, eating too much and the wrong things, and not moving. And that is really the target. But then, we have the tobacco industry, we have the fast food industry, the sugar industry, and all of those who don’t want to have this prevention.
48:42
Russ Roberts: So, I’m going to ask you a tough question. When I read your books, I think–and we did an episode on Gut Feelings, by the way, which I recommend. We’ll put a link to it. I love that book, and I love this book. I love your work. But I have a bias toward Gerd Gigerenzer. I love that you shatter many of the illusions and claims of people who are on the other side. I love that you point out that things that look irrational actually are rational, the heuristics that we use in all kinds of ways, in many parts of life. And, I just wonder if you try–I don’t try so hard, but I can justify that by saying it’s not my life, it’s just my hobby–do you find yourself looking for ways to check your own biases? You have become very identified with a particular viewpoint. You might be wrong, and I’m sure that your identification with that viewpoint makes it harder for you to consume things that don’t always agree with you. So, do you ever feel that unease?
Gerd Gigerenzer: Hm. I mean, that is the business of doing science, that you revise your ideas–
Russ Roberts: It’s hard to do though, science–
Gerd Gigerenzer: I must say, I learn all the time. And, my research group at the Max Planck Institute is deliberately–has never been a group of–so it typically was about 30 to 35 researchers and then not been enough from about a dozen different disciplines. And, it’s deliberate: so that there’s always someone who knows more about something than I know. And there’s always someone from whom I can learn.
And, what is also very important for designing–so at the end of the book, The Intelligence of Intuition, I talk about how to design those smart rules for a research group. And, one of the most important rules is: Hire a contrarian. That is, a person who respectfully disagrees with you as the boss or with the group spirit, and a person who has no fear to disagree on factual basis. And, this is immensely important to correct my own or the group’s biases. And everyone has some preferences about things. So, if Putin would have a contrarian, or Trump, that would be progress.
Russ Roberts: Maybe they do, but they just aren’t that good at it or whatever. Who knows?
Yeah, the line I should have invoked in asking that question was the Feynman line: The first principle is you must not fool yourself, and you’re the easiest person to fool.
And, I know that about myself, so it’s kind of always a challenge, I think. But, the contrarian is a good idea. Could just be your spouse. I float many ideas by my wife, who tells me I’m wrong, which is glorious because she’s not afraid to tell me I’m wrong, and I can learn–if I’m lucky.
Gerd Gigerenzer: I aim for my wife. She takes no prisoners.
Russ Roberts: Exactly.
Gerd Gigerenzer: And, I mean, the best friend is not someone who claps you on the shoulder and nods and finds everything good, like ChatGPT [Generative Pre-trained Transformer] 5: So sycophantic. I can’t stand it. The best friend is someone who criticizes your ideas if there’s something not right and protects you running into a knife outside.
Russ Roberts: That’s awesome.
I haven’t quoted it in a while, but one of my favorite songs is “It Had to Be You.” And, in that song, there’s a verse,
Some others I’ve seen Might never be mean Might never be cross or try to be boss But they wouldn’t do For nobody else gave me a thrill With all your faults, I love you still It had to be you, wonderful you It had to be you.
The music is Isham Jones, and the lyrics, Gus Kahn. It’s a glorious song.
53:30
Russ Roberts: I want to close and talk about morality, which you talk about in the book at some length. And, there are many things that we do and don’t do because we have intuition about them, not because our parents taught us right from wrong, not because our religious beliefs are such. Not that we have a Kantian moral imperative, a categorical imperative that we think, ‘Well, if I did this and everyone did it, then maybe it would be bad.’ Many of the things we do are gut–quick, based on experience, based on a lifetime. And maybe–who knows?–could even be hardwired. But what’s your perspective on the role of intuition and morality?
Gerd Gigerenzer: Yeah. So, let’s start: how do children learn what’s right and wrong? What we know from the studies is that children are made to focus on this issue, what’s right and wrong, as opposed to if it’s an issue about what’s a descriptive issue, what’s in the world and what’s it not involved. And, it is very clear that depending on the culture in which or the parents in which a child grows up, it will take over the moral via rules without–sometimes it’s being said, but most of the time it’s implicit. That is intuitive. And, the reason later is basically used to defend what one doesn’t know explicitly, but feels.
So, for many philosophers, moral reasoning is how it should be, but on the other hand, for Darwin, for instance, the reason why people have morals and religions are to bond a group together, to make it stronger, to survive it in our past against other animals and, most important, other people who are fighting there. And, so, the building the group spirit through moral rules, through religion as an evolutionary function.
And, now, we can debate how important it is today, but in times where science is under attack, as now in many countries, I see that when scientists stand up for the values, this will be much more effective than what I often see today: that people are more timid, that people think about themselves as opposed of a community.
So, moral behavior is mostly true, as you say, through intuitive rules that are not explicit, that people follow, and often then defend after the fact with conscious reasoning, but that has a function. And the function is best captured by saying humans are a social species, and something needs to glue us together to survive, and the something is moral fabric, including religious fabric, including similar things. And, we should not look down at these values that bond us together.
Russ Roberts: My guest today has been Gerd Gigerenzer. His book is The Intelligence of Intuition. Gerd, thanks for being part of EconTalk.
Gerd Gigerenzer: It was a pleasure to talk with you again.
