Human Nature: Stuff and Nonsense

Probably every culture has had at least one theory of human nature, but lately two different and competing notions have dominated intellectual discussion. One, described by Stephen Pinker as the "Blank Slate" theory, holds that human nature is so plastic that behavior is specified almost entirely by culture. The principle alternative argues that much of our behavior derives from instincts that have served to promote our surval over the ages of our evolution. The blank slate notion is much beloved of Marxists and other utopians who think that all we need is the right instruction to produce the perfect human. The instinctive basis has ancient roots, but in it's modern incarnaion owes a lot to sociobiology and evolutionary psychology, which attempt to trace characteristic behaviors to evolutionary advantage, often and controversially when such behaviors seem counterproductive in a modern society.

In practice, almost nobody is a purist. Hardly anybody would deny an instinctive basis for hunger or sex drive, for example. Neither would the hardest core sociobiologist deny the remarkable plasticity of human behavior.

I would argue that this debate is far from purely academic. The twentieth century was littered with the catastrophic failures of socialism, and these failures had much of their root in faulty assumptions about how people would responds to societal design. We also live in an age of massive social experimentation, with new rights and freedoms, with new technologies, and new potential to intervene in the lives of citizens. Should drugs be legalized? Should women serve in the infantry? Should large bottles of sugery drinks be sold? All these questions have something to do with human nature and how it responds to opportunity and risk. More fundamental questions also fit the bill: what should we do or try to do about inequality, if anything? How do we reduce crime rates? How do we promote economic growth? How should we make decisions about what is moral and what is not? what should be legal, and what should not?

I will restate the obvious: I'm firmly in the evolutionary psychology camp. It's a young science and has more questions than answers, but even the kinds of tentative answers it has come up with are of considerable moment.

Consider one example issue. Why does murder happen? If you merely consider it an abberation, you have learned nothing. If you start by examining the historical evidence, though, you see that there are lots of circumstances in which murder is very common, and others in which it isn't. Humans mostly seem to act like we are programmed to murder in some circumstances but not others. Now, if you study the cases, you can see how circumstances can be arranged to make murder less common.