Just So Stories

People who like sociobiology or evolutionary psychology often use just so stories to explain why certain things are as they are. The name “just so stories” is taken from Rudyard Kipling’s book of that name, in which he wrote stories for children about how, for example, the camel got his hump. A typical evolutionary psychology just so story is to argue that women seek higher status men as mates in order to ensure that their children will be protected.

A just so story can be useful and insightful. Unfortunately, it can also be easily mistaken for the truth. In evolutionary theory, the way to ground a just so story is the concept of an evolutionary stable strategy, developed in detail by John Maynard Smith. A just so story can suggest an evolutionary stable strategy; if you can demonstrate such a strategy, then you have a good theoretical explanation for why things are as they are.

However, it is essentially impossible to develop an evolutionary stable strategy for human behaviour. The number of variables is too large, and people will quickly understand the strategy and may seek ways to subvert it. Animals can’t keep track of a hundred individuals and treat them all differently, but people do it routinely. And you can’t run a controlled experiment for human behaviour.

The effect is that for humans a just so story is unfalsifiable. Moreover, human behaviour often has several possible causes. Therefore, in telling just so stories people tend to pick the stories which appeal them on a personal or political level. The fact that one plausible just so story exists may make one think that is the answer, but it’s easy to forget that there may be another just so story which is just as plausible.

As far as I can tell, sociobiology and evolutionary psychology are largely concerned with guesses as to why people act the way they do, mixed in with a considerable set of assumptions as to just how people act. There is very little science to it. I don’t know why the fields get so much attention, beyond the fact that we humans find our own behaviour endlessly fascinating.

When you read a claim like “women seek higher status men so that their children will be protected,” you have to ask yourself some questions. Is that true? Do women really seek higher status men? In particular, is that true across all cultures?

Also, is there another plausible explanation? Perhaps one reason some men have higher status is that they have more charisma–are more likeable–from the point of view of both men and women. Or perhaps women seek higher status men to get more for themselves, without regard to their children. Or perhaps higher status among men is defined by having women pursue them, rather than the other way around–that is, the characteristics we look for when saying that men have higher status are simply the things which we observe cause women to seek them out.

There is no way to test any of these observations, so we don’t really know. The effect is that evolutionary psychology becomes a validator for various theories of folk psychology, rather than a source of insight in itself.