So how does a political commentator end up at neuroscience?

It grew out of my normal day work, which obviously involves politics, but also human capital development. Why, for example, 30 per cent of high school students in the United States drop out, why we got Iraq so wrong. A whole series of policy failures which, in my view, grew out of getting human nature wrong. So I began studying the issue of why so many people drop out of high school, when all the economic incentives are in favour of going to high school. And that took me into the work of an economist called Jim Heckman, at the University of Chicago, who focuses on the first few years of life. And it turns out that already, at age four, you can predict with about 77 per cent accuracy who is going to graduate from high school – based on childhood patterns and things like that. So that got me involved in how these childhood patterns form, which got me involved in brain science, which got me involved in cognitive science…

So, as it’s the one that got you into all this, do you want to tell me a bit about Heckman’s book?

It’s called Inequality in America and it’s by James Heckman and Alan Krueger. Krueger is an economist at Princeton, and presents an opposing point of view. But Heckman’s focus is on what he calls non-cognitive skills. And, basically, cognitive skills are things like IQ, things we’re used to counting. What he calls non-cognitive skills are what the rest of us would call character or personality. And the name non-cognitive is very misleading, because they are cognitive, they are just not conscious, and also not easily quantifiable. So one of the things he looks at is people who, instead of going to high school get GED degrees, which are high school equivalency degrees, degrees that people take if they haven’t been able to go to high school. And often they get test results that are just as high as people who do get high school degrees. But they do much worse in life. In fact, they do no better than high school dropouts. And that’s because they don’t have persistence, they don’t show up at jobs, they don’t have self-control – this is on average, of course. And so his main point, which is obvious to everybody – but not so much to economists – is that having things like persistence and self-control are really important. So where do those things come from? They’re sort of a black box.

And does he answer that question?

No. He is an economist, not a neuroscientist, but he leads us in that direction.

So Krueger is offering another point of view, but you find that section of the book less convincing?

Right. He is more in the ‘inequality is a matter of economic structure’ camp, less to do with human capital.

So in your efforts to answer the question Heckman poses, you ended up reading books about neuroscience proper?

Right. And I started with the easy ones. One very accessible one, but by a guy who is very serious, is a book called The Happiness Hypothesis. It’s by Jonathan Haidt, who is a psychologist at the University of Virginia.

People seem to absolutely rave about this book. One online reviewer says: ‘This is my all-time favourite book. It contains the most practical advice for daily living I have ever seen.’ And a lot of them seem to be like that: ‘The most entertaining, interesting, educational book I have ever read,’ etc, etc. So what does it reveal about the working of our minds?

Haidt uses the metaphor of a boy and an elephant. He says our minds are structured like a boy riding an elephant, and the boy is the conscious reasoning part, the cortex-based brain. And it can see very far, and make certain steering decisions. But most of the work is done by the elephant, which is the unconscious part of the brain. His work is to try to explain what the elephant is doing.

In his research, he focuses especially on moral judgments. So he tells his students the story of a brother and a sister who are off on a trip somewhere. They decide one night they’re going to have sex with each other. They do it, they find it pleasant, and decide they’ll never do it again. But they are glad they did it. And he asks: ‘Is that wrong?’ And most people say it is. But they can’t really explain why they feel that way.

He says that feeling of disgust that we experience is a moral feeling that flows unconsciously, it’s not based on conscious reasoning. And he argues that most of our moral decisions are that kind of an instant reaction. It’s like aesthetics: when we see a scene we know instantly if it’s beautiful or not. We know instantly if something feels moral to us or not.

So the idea that it might be as a result of our upbringing, that we’ve been told that a brother and sister having sex is wrong, but it becomes so firmly ingrained that we don’t even understand why it’s wrong?

I think I would say, and he would say and most scientists would say, that it’s the result of two flows of information. One is the genetic, and in every culture under the sun, incest is regarded as wrong. There is no human culture that really tolerates incest. There’s that sort of knowledge. So we do have some moral knowledge that just comes to us genetically: a sense of fairness, a sense of reciprocity. All humans have these, except psychopaths. So some of that is genetic. But then it’s underlined by cultural things; that’s the second flow of information. And those cultural things may be learned consciously, but are also stored in the elephant.