Question: Why do we overestimate the accuracy of forecasters?
Christopher Chabris: In the area of confidence, we have a lot of trouble properly interpreting the level of confidence that other people express.
A thing we do is we attach too much significant to how confident someone seems and appears and acts. In another sense, we prefer confident people more than less-confident people, even when they’re less accurate and less knowledgeable. So for example, a Dutch psychologist named Gideon Keren did a very clever experiment where he said simply to people, here are two weather forecasters, and they have given the forecast, percentage chance of rain on four consecutive days. Forecaster A says, there’s a 90% chance of rain on Monday, a 90% chance on Tuesday, a 90% chance on Wednesday, and a 90% chance on Thursday. Forecaster B says, there’s a 75% chance on Monday, 75% on Tuesday, 75% on Wednesday and 75% on Thursday.
In fact, after those four days, it turns out to have rained three out of those four days, that is 75% of the days. Which weather forecaster do you think was the better forecaster?
Now, the right answer is Forecaster B because Forecaster B said there was a 75% chance of rain, and he was right. On 75% of those days it actually did rain. He’s what we call perfectly calibrated. But a majority of subjects in this study preferred Forecaster A, and the only difference between Forecaster A and B is that Forecaster A is more confident. Forecaster A is sort of more decisive in his forecasts, but less accurate. Yet we still prefer that forecaster, even knowing their track record.
And here we actually know what their track record is. So we should really be able to say, "Look, this guy got it right, he’s the right one," but instead, even knowing their track record, we go for the one who’s more confident. And this is an unusual case actually because you’ve been given all the information you need to know to make the right decision.
If you think about people who forecast the stock market, or who forecast political elections, or who forecast, you know, trends in shopping and design and so on. We don’t know what the track record of those people are when we pick which ones we like better. So even more seduced by confidence and we don’t realize that we’re paying so much attention to that and we think we’re making a better decision than we really are.
Question: How do the fields of psychology and neurology intersect?
Christopher Chabris: My research is in sort of two areas. One is traditional cognitive psychology and the other is cognitive neuroscience, a more modern field that uses technologies like brain scanning to figure out how what’s going on in the brain explains how our minds work. And these are exciting developments and exciting technologies that enable us to learn those kinds of things and I’m all for them. But, we do point out in our books sort of one unfortunate side effect of some of this new development and we call these side effects "neurobabble" and "brain porn." And "neurobabble" is sort of the adornment of explanations about the mind with references to the brain. A lot of people think that if you can say something about the brain, then you must know more about how the mind works. And it really doesn’t work that way. The brain and the mind are not entirely the same thing Just seeing a picture of the brain with some colorful blobs showing this is where the brain is active while we’re doing some particular task, doesn’t necessarily tell us a whole lot more about that task and how our minds accomplish it.
Likewise, a lot of talk about the brain is often used to sort of... as an add on to other arguments to make them seem more convincing as sort of like an all-purpose you now, reference to make your argument more convincing. To say it has something to do with the brain and show a picture of the brain and so on. Advertising does this quite a bit as well. You can see the brain, if you look, in all kinds of advertisements where when you think about it, it’s really not that relevant. And I sort of am a little bit troubled about that trend, while at the same time I think that it’s exciting to discover more about the brain just as long as we know what the knowledge means and that it doesn’t mean that traditional psychology is somehow obsolete and replaced by neuroscience and so on.
They are two topics of study that definitely relate to each other quite a bit, but the one doesn’t replace or really make the other any more credible.
Recorded on May 13, 2010
Interviewed by Austin Allen