Monday, 2 January 2017

David Queller on the cultural origins of xenophobia

David Queller recently proposed the hypothesis that xenophobia evolved due to "isolation mismatch" - David's proposed name for the idea of cross-species incompatibility and infertility.

Having "mule" offspring is sometimes harmful - worse than having no offspring at all. Queller proposes that analogous cultural mismatches can produce broadly similar harmful effects - as memes battle with incompatible companions and generally fail to work together. He gives examples and argues that mechanisms to avoid these bad outcomes could result in xenophobia - via genetic and/or cultural evolution.

David's ideas here are obviously important and worthwhile - but I'm rather skeptical about whether "isolation mismatch" is largely responsible for xenophobia. Humans cooperate in part due to reciprocity and cultural kin selection. In the absence of those effects they can behave pretty badly. If you are a caveman, you don't bash in the brains of a member of a neighboring tribe because you are concerned about cultural mismatch. You do it because they are a competitor and would likely do the same to you given half a chance. Xenophobia is pretty well explicable as a baseline state that arises when the mechanisms responsible for cooperation are absent. That's not to say that divergent selection as a result of cultural mismatches due to isolation is unimportant, but that it may be only a small part of the story of the origins of xenophobia.

Much the same argument applies to explanations for xenophobia that invoke the cost of producing genetic mules. Mules do exist and do have significant costs, but a lot of xenophobic behavior is not directly associated with the production of mules. That hypothesis would predict more female xenophobia - since females bear most of the cost of bearing mule offspring. In fact, xenophobia is more likely to be exhibited by males (see reference below). Rivalry and competition for mates seem like more appropriate explanations for that than the costs of producing mules.

Finally, I'm completely onboard with David when he writes:

Indeed understanding the roots of xenophobia might provide ways to mitigate it.
This is one of the ways in which cultural kin selection is of great social and political importance. Aside from it being of scientific interest, there's also the issue of it providing scope for improving the scope of human cooperation by engineering and promoting shared memes.



  1. "females bear most of the cost of bearing mule offspring"

    This isn't automatically the case. From a female point of view, the most important thing in an offspring is future viability, regardless of the father. If foreigners are perceived to produce more viable offspring, they will be preferred as sexual partners.

    Groups naturally emerge because individuals have a feel for which people are more likely to form in-groups with them, and which are likely to form their own in-groups, excluding them. One reason why men are more xenophobic may very well be that any new "type" of individual that is likely to form their own in-group is perceived as a threat, both to themselves and to their offspring. Men have only to lose if their current in-group is threatened. Females don't, as their genetic heritage will go on no matter what.

  2. I sense a misunderstanding here. By "mule offspring" I mean "offspring with infertility due to outcrossing". The concept is all about future viability - rather than being to do with the identity of the of the father. Mule offspring are more negative for the sex with the greater parental investment - which is usually females.