This approach is new to the study of animal cognition, as well as the study of human cognition. What makes this approach powerful is that it then leads us to studies of the human brain. We therefore begin to create an intimate connection between the thoughts and the neural-mechanisms that underlie them. For example, why can't animals find the correct location of a falling object through a tube? Why can't they inhibit their biases, and search in a different location? We now know from studies of the evolution of the brain that the frontal parts of our brain have undergone extraordinary evolution over the past five to six or more millions of years. If we compare the relative size of the frontal regions of our brains, relative to a primate of our size, it's about two hundred percent bigger than you predict. So in a monkey species like the tamarins that I study in captivity, that part of the brain is greatly impoverished relative to its capacity in the human brain. What we find is that prefrontal region of our brain is the part of the brain that's engaged in blocking repetitive responses. So for example when unintentially bump into a glass door, we may do that once because we fail to notice that it's glass, but we won't repeat that error over and over again. We have a mechanism that's specifically designed to inhibit those kinds of actions. That is something that really did not evolve in a significant way within many non-human animal species. So what's exciting to me is that we really have a deep connection between the ecology and social behavior of the species, the mental states they bring to the task of solving the problems, and then a further step back, into the brain seeing how the brain evolved to meet those particular problems. And that's a unique marriage today.

JB: What other scientists do you relate to?

HAUSER: The people that I have the most convergence with, or interest in their thinking and work are probably the psychologist Stephen Pinker and the philosopher Dan Dennett. To finish the disciplinary areas, I would add Richard Dawkins. What has continued to amaze and intrigue me about these three is their incredible ability to explicate very complicated theories in evolutionary biology. When I was an undergraduate, my first course in evolutionary biology was based on Ed Wilson's recently published book Sociobiology. That was the first book I read in the field, and then immediately went on to read Dawkins's The Selfish Gene. What struck me was the richness of ideas in this field, and extraordinary clarity with which Dawkins expressed them. I was also impressed by the lack of empirical workat the time, but could immediately see how the empirical work would come. And it did, volumes and volumes of it. Dawkins has an exceptional ability to take these difficult ideas, which often required pages and pages of algebra to explain in the original papers, and provide just the most elegant metaphors to explain them. The downside of Dawkins' book is that people who don't understand the biology often read them and conclude that this is a very trivial, simple field, whereas they really haven't grasped the fundamental problems. I suppose this is why Richard, when asked why he keeps writing the same book, says that it's because people continue to fail to understand him. The fact that he writes so clearly makes it seem that the biology is very, very, easy, and that's a potential problem.

Steve Pinker is another one of these people who just have the most remarkable ability to think clearly about difficult problems and then write about them in an entertaining way. Steve also suffers from the same problems Dawkins suffers from. Critics often don't read in depth through the books or articles that Steve writes. They extract snippets or pull out columns Steve writes in The New York Times, and then make faulty conclusions. Natalie Angier recently wrote a piece in The New York Times Magazine section, criticizing evolutionary psychology and pulling out Steve Pinker as one of the major problems for that field.