Are left and right a feature (or bug) of evolution?
And thus we enter the realm of full-blown, and inevitably highly controversial, evolutionary explanations. Tuschman doesn’t hold back. Conservatives, he suggests in one of three interrelated evolutionary accounts of the origins of politics, are a modern reflection of an evolutionary impulse that leads some of us to seek to control sexual reproduction and keep it within a relatively homogenous group. This naturally makes today’s conservatives more tribal and in-group oriented; if tribalism does anything, it makes it clear who you are and aren’t supposed to mate with.
Tuschman’s liberals, in contrast, are a modern reflection of an evolutionary impulse to take risks, and thereby pull in more genetic diversity through outbreeding. This naturally makes today’s liberals more exploratory and cosmopolitan, just as the personality tests always suggest. Ultimately, Tuschman bluntly writes, it all comes down to “different attitudes toward the transmission of DNA.” And if you want to set these two groups at absolute war with one another, all you need is something like the 1960s.
According to Tuschman, these competing reproductive strategies arise from the fact that there are advantages to keeping mating close within the group, but also advantages to mixing in more genetic diversity. Moreover, there is a continuum from extreme inbreeding to extreme outbreeding, featuring many different reproductive strategies along the way. Thus, we see in other species, such as birds like the great tit, a range in mating behavior, from a high level of breeding with more closely related birds to a high level of outbreeding.
Outbreeding brings in diversity, which is vital. For instance, diversity in the genes that create the proteins that ultimately come to comprise our immune systems has obvious benefits. But outbreeding also has risks—like encountering deadly new pathogens when you encounter new human groups—even as a moderate degree of inbreeding appears to have its own advantages: perpetuating genetically based survival strategies that are proven to work, increasing altruism that arises in kin relationships, and also, it appears, having more total offspring.
Extreme inbreeding, to be sure, is deleterious. But Tuschman presents evidence suggesting that there is an optimum—at around third-cousin or fourth-cousin mating—for producing the largest number of healthy offspring. He also shows related evidence in Danish women suggesting that a moderate degree of geographic dispersal to find a mate (measured by the distance between a woman’s birthplace and her husband’s) is related to having a high number of children, but too much dispersal and too little are both related to less overall fertility.
Returning to the present, Tuschman emphasizes that conservatives, and especially religious conservatives, always want to seem to control and restrict reproduction (and other sexual activities) more than liberals do. It’s understandably hard for an evolutionary biologist not to see behaviors that systematically affect patterns of reproduction in a Darwinian light.
And it’s not just reproductive patterns: Tuschman also suggests that other aspects of the liberal-conservative divide reflect other evolutionary challenges and differential strategies of responding to them. He traces different left-right views on hierarchy and equality to the structure of families (a move that cognitive linguist George Lakoff has in effect already made) and the effect of birth order on the personalities and political outlooks of siblings. And Tuschman traces more positive and negative (or, risk-aversive) views of human nature on the left and the right to different types of evolutionarily based altruism: altruism toward kin on the conservative side, and reciprocal altruism (which can be toward anyone) on the liberal side.
But is all of this really true? Tuschman’s book is difficult to evaluate on this score. It says so much more about evolution than Hibbing, Smith, and Alford do, and yet manages to do so without leaving the same impression about the importance of caveats and nuances. Is Tuschman advancing a group selection theory, or not? It sometimes sounds like it, but it isn’t clear. And most importantly, is the variation among humans of politically relevant traits just part of the natural order of things, or does it itself reflect something about evolution? Again, it isn’t clear. This is not to suggest that Tuschman lacks a view on such questions; it’s just that he synthesizes so much scientific evidence that this kind of hand-holding seems less of a priority.
In the end, Tuschman’s book attempts a feat that those of us monitoring the emerging science of politics have long been waiting for—explaining the now well-documented psychological, biological, and genetic differences between liberals and conservatives with reference to human evolution and the differential strategies of mate choice and resource allocation that have been forced on us by the pressures of surviving and reproducing on a quite dangerous planet. It may or may not stand the test of time, but it certainly forces the issue.
In the end, what’s so stunning about all of this is the tremendous gap between what scholars are learning about politics and politics itself. We run around shutting down governments and occupying city centers—behaviors that can only be driven by a combination of intense belief and equally intense emotion—with almost zero perspective on why we can be so passionate one way, even as our opponents are passionate in the other.
To see politics as Hibbing, Smith, Alford, and Tuschman see it, by contrast, is inevitably to want to stop fighting so much and strive for some form of acceptance of political difference. That’s why, even though not all of the answers are in place yet, we need their line of thinking to catch on. Ideological diversity is clearly real, deeply rooted, and probably a core facet of human nature. Given this, we simply have no choice but to come up with a much better way to live with it.
Buy these books from Amazon and support Washington Monthly: Predisposed: Liberals, Conservatives, and the Biology of Political Differences
Feed the Political AnimalDonate
Washington Monthly depends on donations from readers like you.