David Buller’s book, Adapting Minds, is in the news again. I agree with Mixing Memory that many of Buller’s specific debunkings – such as his full-throated attack on the cheater module – seem flimsy. (And trust me, I was prepared to believe…In my humble opinion, too much evolutionary psychology seems unrigorous , unempirical, and designed for the express purpose of selling bad books.)
That said, I still think Buller’s tome made an important point. While most critics of evolutionary psychology continue to borrow from Lewontin and Gould’s old playbook – the debate includes an unwieldy amount of architectural metaphors – Buller attacked evo pysch from the perspective of modern neuroscience. Personally, I find this to be a much more potent argument. When evo psych emerged from the controversial rubble of sociobiology, neural plasticity consisted of a few kinase enzymes and some rumors about LTP. Now we know better. In fact, the causes and effects of neural plasticity – from enriched environments to neurogenesis – are, without a doubt, the most important theme in modern neuroscience.
Of course, this doesn’t mean our brain is a blank slate, or some mushy ball of play dough. In his book, Buller proposes an apt metaphor: our mind is like the immune system. In other words, while a genetic program specifies the gross anatomy of our brain, the all important details are determined by experience. Just as our antibodies are constantly altered in response to the pathogens we actually encounter (we do not have the B-cells of our parents, or of our identical twin), the brain is constantly adapting to the particular conditions of our own life. This is why blind people can use their visual cortex to read Braille, and why the deaf can process sign language in their auditory cortex. Lose a finger and, thanks to neural plasticity, your other fingers will take over its brain space. In one particularly audacious experiment, the neuroscientist Mriganka Sur literally re-wired the mind of a ferret, so that the information from its retina was plugged into its auditory cortex. To Sur’s astonishment, the ferrets could still see. Furthermore, their auditory cortex now resembled the typical ferret visual cortex, complete with spatial maps and neurons tuned to detect slants of light.
So how has evo psych modified its theories in response to plasticity? You’d think they might revise their notions of massive modularity, or spend some of their considerable brainpower theorizing about the evolution of plasticity. But you’d be wrong. Evo psych continues its old obsession with sexual selection, innate modules, and the more nefarious aspects of human nature. That’s all well and good, but I still hope that one day evo psych decides to spend less time hypothesizing about our EEA, or inscrutable Pleistocene ancestors, and more time poring over the molecular details of our mind. Hopefully, Buller’s overzealous critique will jumpstart this process.