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

I was once a devout member of the Church of Evolutionary Psychology.

I believed in modules — lots of them. I believed that the mind could be thought of as a confederation of hundreds, possibly thousands, of information-processing neural adaptations. I believed that each of these mental modules had been fashioned by the relentless winnowing of natural selection as a solution to problems encountered by our hunter-gatherer ancestors in the Pleistocene. I believe I actually said that we were living in the Space Age with brains from the Stone Age. Which was clever — but not, it turned out, particularly wise.

Along with the Church Elders, I believed that this was our universal evolutionary heritage; that if you added together a whole host of these
domain-specific mini-computers — a face recognition module, a spatial relations module, a rigid object mechanics module, a tool-use module, a social exchange module, a child-care module, a kin-oriented motivation module, a sexual attraction module, a grammar acquisition module and so on —  then you had the neurocognitive architecture that comprises the human mind. Along with them, I believed that what made the human mind special was not fewer of these 'instincts', but more of them.

I was so enchanted by this view of life that I used it as the conceptual scaffolding upon which to build a multi-million dollar critically- acclaimed PBS series that I created and hosted in 1996.

And then I changed my mind.

Actually, I prefer to say that I experienced a conversion. My
conversion — literally, the turning around — the adoption of new beliefs was prompted primarily by conversations. First and foremost with an apostate from the Church of Evolutionary Psychology's inner sanctum (Peggy La Cerra); then with a group of colleagues including neuroscientists, evolutionary biologists and philosophers. Two years later, La Cerra and I published in PNAS an alternative model of the mind and followed that with a book in 2002.

Although this is not the place to detail the arguments, we suggested that the selective pressures of navigating ancestral environments — particularly the social world — would have required an adaptively flexible, on-line information-processing system and would have driven the evolution of the neocortex.  We claimed that the ultimate function of the mind is to devise behavior that wards off the depredations of entropy and keeps our energy bank balance in the black. So our universal evolutionary heritage is not a bundle of instincts, but a self-adapting system that is responsive to environmental stimuli, constantly analyzing bioenergetic costs and benefits, creating a customized database of experiences and outcomes, and generating minds that are unique by design.     

We also explained the construction of selves, how our systems adapt to different 'marketplaces', and the importance of reputation effects — a richly nuanced story, which explains why the phrase "I changed my mind" is, with all due respect, the kind of rather simplistic folk psychological language that I hope we will eventually clean up. I think it was Mallarmé who said it was the duty of the poet to purify the language of the tribe. That task now falls also to the scientist.

This model of the mind that I have now subscribed to for about a decade is the bible at the Church of Theoretical Evolutionary Neuroscience (of which I am a co-founder). It was created in alignment with both the adaptationist principles of evolutionary biologists and psychologists (who, at the time, tended to pay little attention to the actual workings of the brain at the implementation level of neurons) and the constructivist principles of neuroscientists (who tended to pay little attention to adaptationism). It would be unrealistic, however, to claim that the two perspectives have yet been satisfactorily reconciled. 

And this time, I am not so devout.

Some Evolutionary Psychologists promoted their ideas with a fervor that has been described as evangelical. To a certain extent, that seems to go with the evolutionary territory: think of the ideological feuds surrounding sociobiology, the renewed debates about levels of selection and so on. Of course, it could be argued that the latest subfields of neuroscience (like neuroeconomics and social cognitive neuroscience) are not immune to these enthusiasms (the word comes from the Greekenthousiasmos: inspired or possessed by a god or gods). Think of the fMRI-mediated  neophrenological explosion of areas said to be the neural correlate of some characteristic or other; or whether the mirror neuron system can possibly carry all the conceptual freight currently being assigned to it.

Even in science, a seductive story will sometimes, at least for a while, outpace the data. Maybe that's inevitable in the pioneering phase of a fledgling discipline. But that's when caution is most necessary — when the engine of discovery is running more on faith than facts. That's the time to remember that hubris is a sin in science as well as religion.