In Quillette Hrishikesh Joshi and Jonny Anomaly* ask Are Liberals Dying Out? Since the piece has been shared a fair amount (judging by my Twitter timeline), I thought I should respond to why I don’t think that is a major concern. Let me jump to their last paragraph:
Nevertheless, despite cultural trends, the best available evidence suggests that political ideology is heritable, and that people with liberal personality traits currently have far fewer children than conservatives. If this trend continues, it is possible that the reproductive choices people are making today will influence the political climate of future generations. Over the long run, conservatives could end up winning the ideological contest with fertility rather than arguments.
I agree that political orientation seems heritable. That is clear in books like Born That Way. But heritability expresses itself in an environmental context. If you had a totalitarian government most of the phenotypic variation would disappear. Yes, there would be dissidents, but they’d be freaks. Most humans would conform (no, I don’t think the citizens of Soviet Russia were genetic freaks unable to grasp freedom like Howard Roark). The correlation between religiosity and fertility varies by society as well. The more secular the society, the bigger the gap (though last I checked this was not true in China). In a totally conservative future heritable variation for liberalism could just reemerge.
Second, political orientation exists on a relative plane. If one imagines it as some specific thing, or disposition, one can imagine that in the future the liberal-conservative spectrum would exist, but just be shifted. Quantitative genetics has shown that selection can move the mean many standard deviations. I don’t think this is a strong objection to their overall point, but it gets at the fact that we view liberal-conservative tendencies along a distribution (1980s liberal commentator Jeff Greenfield was widely known for making disparaging comments about gays i the prime of his career; that did not destroy his career as a liberal pundit at that time). Perhaps liberal have already won in an age when most conservatives understand and accept that gay marriage is here to stay.
Third, some of the variation is not heritable. It’s random. In fact around half of it within the population. Some people may just be liberal for stochastic reasons. You aren’t going to get rid of this with selection.
Perhaps most essential in terms of theory: frequency dependence. The dynamics of human interaction and decision making are such that the frequency of liberals declining might have an impact on their fitness. To give a weird example, perhaps an economically post-Malthusian society needs a certain number of sub-replacement liberals who engage in particularly productive work to maintain itself. If society slouched rapidly back toward Malthusianism perhaps everyone would just trudge along at replacement.
The big picture problem is assuming constant directional selection and exhaustion of heritable variation is all well and good when you are selecting for wax-seed oil, but human societies are non-linear systems which are subject to big shocks. They aren’t controlled agricultural genetic experiments.
Finally, let me use an analogous case to make an empirical objection. Many people tell me that the future will be religious due to the same dynamics above. This despite the century long trend toward secularization (parenthetical, God is Back was an ill-timed books, as the United States was shifting toward secularization at that time).
But I want to go back further. France was the first nation to start the demographic transition. In the early 19th century the secular elite was worried about the fertility of devout Roman Catholics, in particular the Poles who were arriving. The secular future they envisioned was threatened. It’s been nearly 200 years since these worries, and in those 200 years France has become more and more secular.
My point with this illustration is that if your theory can not predict the past, it can’t predict the future. At least not robustly. Liberal people will always be with us. So will shy people. And atheists too. They may wax and wane, but human variation persists. On the evolutionary genetic level I think frequency dependent dynamics are such that the fait, in the medium term, of low fitness traits is generally to become oddballs, not extinct. And once they are odd they may become fortunes favorites….
* For real, is that his real name?