So we are told at ScienceDaily:
According to this new model developed by researchers DB Krupp (Psychology) and Peter Taylor (Mathematics and Statistics, Biology) at Queen’s and the One Earth Future Foundation, individuals who appear very different from most others in a group will evolve to be altruistic towards similar partners, and only slightly spiteful to those who are dissimilar to them.
However, individuals who appear very similar to the rest of a group will evolve to be only slightly altruistic to similar partners but very spiteful to dissimilar individuals, often going to extreme lengths to hurt them. Taken together, individuals with ‘common’ and ‘rare’ appearances may treat each other very differently.
This finding is a new twist on established evolutionary theory and could help explain racism and corresponding forms of prejudice in humans and other species.
“Similar individuals are more likely to share copies of each other’s genes and dissimilar individuals are less likely to. As a consequence, evolutionary theory predicts that organisms will often discriminate, because helping similar partners and harming dissimilar ones increase the fraction of the discriminating party’s genes in future generations,” says Dr. Krupp.
This model is based on the much-disputed inclusive fitness (group selection) theory.*
First, beware of any sciencey claim to “explain” a facet of human nature; it is necessarily based on philosophical assumptions. In this case, they are those of evolutionary psychology, another Darwinian discipline without a subject. The “subject” died a million years ago on the African plains, but the evolutionary psychologist claims to have heard his voice in our genes. Just as the astrobiologist can tell us about space aliens and also why they don’t ever show up.
On a serious note, most racism is driven by specific cultures, as anyone with knowledge of the world will see. Today, it is often fronted consciously for political gain.
Racism declines in situations where it is not accepted, genes notwithstanding. The armed forces of many western nations played a role in this, because once the system itself stopped fronting racism, the chain of command necessarily overruled local prejudice. (Governments “outlawing” racist thinking doesn’t really work; it must be seen as low class or not cool or evidence of stupidity if it is to decline in importance.)
I remember growing up in Canada mid-century when it was a point of pride among our teachers to criticize the southern U.S. states for “backward” attitudes in that respect (since much changed, of course). It was pointed out to us that our own country belonged to a commonwealth of nations of many races, ethnicities, and languages, all of whom had the same head of state, Elizabeth II. And Elizabeth must treat all the citizens of all the commonwealths equally, and honour those to whom honour is due. Thus, an ignorant, obscure Southern belle might refuse to dance with a black man, but Elizabeth, of course, danced with African dignitaries, as was the international custom.
You can think it is all malarkey, but there have been comparatively few race riots in places I have lived where these values were taught and enforced—despite the allegedly awesome power of inclusive fitness, etc.
* For the inclusive fitness dispute, see, for example, Why the uproar around E. O. Wilson’s new “group selection book? And Electrifying the corpse: The reaction to E. O. Wilson disowning Darwinian kin selection (a concept he largely invented) And that’ll likely be as much as you even want to know about this pseudo-discipline.
Here’s the abstract:
The persistence of altruism and spite remains an enduring problem of social evolution. It is well known that selection for these actions depends on the structure of the population—that is, on actors’ genetic relationships to recipients and to the ‘neighbourhood’ upon which the effects of their actions redound. Less appreciated, however, is that population structure can cause genetic asymmetries between partners whereby the relatedness (defined relative to the neighbourhood) of an individual i to a partner j will differ from the relatedness of j to i. Here, we introduce a widespread mechanism of kin recognition to a model of dispersal in subdivided populations. In so doing, we uncover three remarkable consequences of asymmetrical relatedness. First, altruism directed at phenotypically similar partners evolves more easily among migrant than native actors. Second, spite directed at dissimilar partners evolves more easily among native than migrant actors. Third, unlike migrants, natives can evolve to pay costs that far outstrip those they spitefully impose on others. We find that the frequency of natives relative to migrants amplifies the asymmetries between them. Taken together, our results reveal differentiated patterns of ‘phenocentrism’ that readily arise from asymmetries of relatedness. (paywall) – D. B. Krupp, P. D. Taylor. Social evolution in the shadow of asymmetrical relatedness. Proceedings of the Royal Society B: Biological Sciences, 2015; 282 (1807): 20150142 DOI: 10.1098/rspb.2015.0142