Politics, personality, and hand-waving

In Washington Monthly, Chris Mooney has reviewed two new books that synthesize what we know to date about how our political outlooks are related to our personalities. The review is worth reading in its entirety, and it raises some interesting points about evolution, personality, and politics.

However, I was struck by one thing that I wanted to mention because it seems representative of a particular type of statement about evolution that really bugs me: the simplistic application of a single complex evolutionary phenomenon to some complex contemporary situation. To wit:

Again and again, when they take the widely accepted Big Five personality traits test, liberals tend to score higher on one of the five major dimensions—openness: the desire to explore, to try new things, to meet new people—and conservatives score higher on conscientiousness: the desire for order, structure, and stability. … And this finding is highly consequential, because as [both books] note, people tend to mate and have offspring with those who are similar to them on the openness measure—and therefore, with those who share their deeply rooted political outlook. It’s a process called “assortative mating,” and it will almost certainly exacerbate our current political divide.

It’s the last part of the last sentence that got to me. My gripe is essentially that assortative mating has, as far as we know, been going on for a very long time, through various kinds of political arrangements and balances of power between liberals and conservatives,1 and it’s hard to see how it could affect our current political divide except in the broadest sense that it presumably has some effect on what kind of species we are.

If it has produced a mixed bag of personality traits (not to mention physical traits) so far (as Mooney discusses later in the review), why should we believe that it’s going to somehow worsen a very recent (in evolutionary terms, not even the blink of an eye) situation that involves a very particular history and set of political institutions?

My point is not that assortative mating is unimportant to human societies, just that mate choice is complicated, and we don’t know enough right now to say anything meaningful about how it affects specific contemporary political situations (or maybe even broader questions of human nature overall). People may look for many types of similarity in a mate: other personality traits, looks, socioeconomic status, level of education, religion, and intelligence, for example. Not only that, but they may also sometimes look for dissimilarity, or things that aren’t really about similarity or difference.

People do try to educate their children according to their beliefs, but again, this has been going on forever, and the results are mixed. The apple sometimes does fall pretty far from the tree. More importantly, if this could be described as evolution at all, it’s cultural evolution, not biological evolution, and it’s got nothing to do with assortative mating.

I bring this up not just to vent, but also because this sort of oversimplification is an obstacle to fruitful discussion of how human evolution has affected human nature and the societies we create. This is a complex topic that involves aspects of our lives that we’re sensitive about; our data are limited at the moment. Still, it’s a subject of endless interest, which is all the more reason to be careful how we talk about it.


1 The liberal/conservative distinction has been used in most of the research into politics and personality that has hit the news, and it’s the focus of Mooney’s review, but it will be nice when the research has developed to the point where it can consider more sophisticated categories. It would be useful to have at least a second axis, as in the Political Compass system. Current research into personality and politics is fascinating, but it’s just beginning.