Last month, I interviewed psychologist Daniel Kahneman, who won the Nobel Prize in economics in 2002 and recently authored the book Thinking, Fast and Slow.

Kahneman has been a pioneer in the field of behavioral psychology, changing the way we think about human behavior. So I asked him: "What do you want to know that you still don't know?"

Here's how he answered (transcript follows):

Dr. Kahneman: At the moment, psychology is moving to brain science and what that's going to do, and only a fool will really try to predict, except that we can be pretty sure that the whole field will look completely different in 20 or 30 years as a result of the mix of brain science with psychology, but what specific questions will be answered, no idea really.

There is one question that I'm curious about, but it's a small one that if I had been younger and active in research, I would have tried to pursue. And these are the health consequences and the health, the relationship between health and wellbeing and psychological wellbeing is really very interesting to me. How does it work? Because there seems to be a connection, but how does the connection work? That's something that I would have liked to know.