2008 : WHAT HAVE YOU CHANGED YOUR MIND ABOUT? WHY?

As a student, I was influenced by Claude Lévi-Strauss and even more by Noam Chomsky. Both of them dared talk about "human nature" when the received view was that there was no such thing. In my own work, I argued for a naturalistic approach in the social sciences. I took for granted that human cognitive dispositions were shaped by biological evolution and more specifically by Darwinian selection. While I did occasionally toy with evolutionary speculations, I failed to see at the time how they could play more than a quite marginal role in the study of human psychology and culture.

Luckily, in 1987, I was asked by Jacques Mehler, the founder and editor of Cognition, to review a very long article intriguingly entitled "The logic of social exchange: Has natural selection shaped how humans reason?" In most experimental psychology articles the theoretical sections are short and relatively shallow. Here, on the other hand, the young author, Leda Cosmides, was arguing in an altogether novel way for an ambitious theoretical claim. The forms of cooperation unique to and characteristic of humans could only have evolved, she maintained, if there had also been, at a psychological level, the evolution of a mental mechanism tailored to understand and manage social exchanges and in particular to detect cheaters. Moreover, this mechanism could be investigated by means of standard reasoning experiments.

This is not the place to go into the details of the theoretical argument — which I found and still find remarkably insightful — or of the experimental evidence — which I have criticized in detail with experiments of my own as inadequate. Whatever its shortcoming, this was an extraordinarily stimulating paper, and I strongly recommended acceptance of a revised version. The article was published in 1989 and the controversies it stirred have not yet abated.

Reading the work of Leda Cosmides and of John Tooby, her collaborator (and husband), meeting them shortly after, and initiating a conversation with them that has never ceased made me change my mind. I had known that we could reflect on the mental capacities of our ancestors on the basis of what we know of our minds; I now understood that we can also draw fundamental insights about our present minds through reflecting on the environmental problems and opportunities that have exerted selective pressure on our Paleolithic ancestors.

Ever since, I have tried to contribute to the development of evolutionary psychology, to the surprise and dismay of some of my more standard-social-science friends and also of some evolutionary psychologists who see me more as a heretic than a genuine convert. True, I have no taste or talent for orthodoxy. Moreover, I find much of the work done so far under the label "evolutionary psychology" rather disappointing. Evolutionary psychology will succeed to the extent that it causes cognitive psychologists to rethink central aspects of human cognition in an evolutionary perspective, to the extent, that is, that psychology in general becomes evolutionary.

The human species is exceptional in its massive investment in cognition, and in forms of cognitive activity — language, higher-order thinking, abstraction — that are as unique to humans as echolocation is to bats. Yet more than half of all work done in evolutionary psychology today is about mate choice, a mental activity found in a great many species. There is nothing intrinsically wrong in studying mate choice, of course, and some of the work done in this area is outstanding.

However the promise of evolutionary psychology is first and foremost to help explain aspects of human psychology that are genuinely exceptional among earthly species and that in turn help explain the exceptional character of human culture and ecology. This is what has to be achieved to a much greater extent than has been the case so far if we want more skeptical cognitive and social scientists to change their minds too.