NO TWO LOOK ALIKE

As she did in The Nurture Assumption (1998), independent scholar Harris makes waves again with a new theory of personality to explain why no two people are alike.

Based on behavioral genetics and evolutionary and social psychology, and fitted into a modular theory of how the brain works (e.g., you have a face-recognition module, a categorization module), she posits three distinct systems as the molders of personality. One is a relationship system that allows babies to distinguish family from strangers and throughout life allows us to build a “mental rolodex” of information on discrete individuals. The second is a socialization system. Sure, parents count, she says, but what turns us into social beings is what happens in school and at play, as we become members of a group, learn the pecking order and absorb the group’s culture within the larger cultural context. Third is a status system by which we acquire self-knowledge by measuring how we stand up against rivals, and want to beat them out. These dynamics play out against a hefty genetic contribution that makes individuals more or less aggressive, shy, anxious, attractive and so on. There’s a lot to be said in favor of these systems (and genes), and Harris lays out telling points in their defense—while also laying out some of the leading lights of personality psychology for their sins of omission and commission. But is that all? There is something a little too rational and static, a little too game-theoretical in Harris’s approach. Sure the systems can explain, as Harris set out to do, why identical twins raised together have distinct personalities. But the model needs tweaking not only to deal with overlaps across systems, but also to explain how individuals change group dynamics: What forces create the personalities who are the movers and shakers as opposed to those moved and shaken by “the systems”?

Credit Harris for moving personality away from simplistic theories—but not far enough away—and expect some lively rebuttals.