Recently the great JayMan has been on a rampage against the concept of ethnic genetic interests.  He writes:

The gist of this idea is that the presence of outsiders supposedly increases the relative relatedness between unrelated co-ethnics, since (according to the theory) relationship would be judged relative to the total genetic background involved.

The problem is that this reasoning is flawed. The normal way of assessing kinship, the coefficient of relationship, is as follows (from Wikipedia):

Degree of
relationship
Relationship Coefficient ofrelationship (r)
0 identical twins; clones 100%
1 parent-offspring 50% (2−1)
2 full siblings 50% (2−2+2−2)
2 3/4 siblings or sibling-cousins 37.5% (2−2+2⋅2−4)
2 grandparent-grandchild 25% (2−2)
2 half siblings 25% (2−2)
3 aunt/uncle-nephew/niece 25% (2⋅2−3)
4 double first cousins 25% (2−3+2−3)
3 great grandparent-great grandchild 12.5% (2−3)
4 first cousins 12.5% (2⋅2−4)
6 quadruple second cousins 12.5% (8⋅2−6)
6 triple second cousins 9.38% (6⋅2−6)
4 half-first cousins 6.25% (2−4)
5 first cousins once removed 6.25% (2⋅2−5)
6 double second cousins 6.25% (4⋅2−6)
6 second cousins 3.13% (2−6+2−6)
8 third cousins 0.78% (2⋅2−8)
10 fourth cousins 0.20% (2⋅2−10)

As we can see, the coefficient of relationship drops to insignificance beyond second cousins. This is the probability that a given relative of an individual possesses a copy of an allele the individual possesses. This affects kin selection given by Hamilton’s rule (also from Wikipedia):

rB > C

where

r = the genetic relatedness of the recipient to the actor, often defined as the probability that a gene picked randomly from each at the same locus is identical by descent.
B = the additional reproductive benefit gained by the recipient of the altruistic act,
C = the reproductive cost to the individual performing the act.

When this is inequality is true, the altruistic trait is selected for.

An altruistic allele leads to behavior that makes this inequality true will tend to increase in frequency in the population. All other altruistic alleles will decrease with time. This is the basis of kin selection…Salter’s/Harpending’s/Rushton’s idea for ethnic nepotism doesn’t work for this key reason: the presence of outsiders doesn’t alter the frequency of altruistic alleles. The payoff remains the same in both cases.

JayMan is citing Hamilton’s rule which argues that if an uncle sacrifices his life to save four of his nephews, each of whom share a quarter of his genes, it’s the equivalent of saving himself.

However after much abstract thought and concentration, Hamilton himself realized the limits of this model, which is that within a species, natural selection is relative, not absolute, so while co-ethnics are not cousins, technically speaking, they are analogous to cousins compared to the total amount of human genetic variation.  If a childless Bantu sacrifices his life to save eight unrelated Bantus, he’s decreased his genetic fitness relative to other Bantus, but he’s greatly increased his genetic fitness relative to a childless British person who saves no other British people, because in the next generation, there are more alleles and combinations of alleles that resemble the childless but heroic Bantu than the childless and selfish Brit.  And the Bantu who manages to save eight other Bantu without losing his own life, has increased his genetic fitness even more.

As Hamilton noted, when groups compete for resources, the greater the genetic distance between groups, the more you increase your genetic fitness by helping your group.

A few months ago, someone sent me a brilliant email (perhaps citing Hamilton himself), noting that if humans found themselves under attack by space aliens, whose genetic distance from humans could be considered infinite, all humans would be as perfectly related as genetic clones, and so a Bantu saving a British person under this scenario would be as fitness enhancing as a Bantu saving his identical twin under normal conditions.

The concept of relative selection is very difficult for even brilliant scientists to grasp because it requires you to think abstractly instead of concretely, and considering both within group fitness and between group fitness simultaneously overloads the working memory of even the greatest minds.  But after much intense focus, Hamilton himself was one of the first to make the leap.

Hamilton felt that because conflicts between genetically distant humans were likely common throughout much of human evolution (i.e. modern humans vs Neanderthals), natural selection likely gave humans implicit processing systems that allowed us to mate and befriend genetically similar others, especially during times of tribal conflict.

This helps to explain the existence of civil rights martyrs who die for their people (Martin Luther King), and soldiers willing to die for their country, and Palestinian suicide bombers, none of which would make evolutionary sense if Hamilton’s rule were absolute instead of relative, because under an absolute paradigm, these acts would be too costly to have evolved.

It also explains, as Hamilton noted, why societies are not limited to extended families, why wars occur between entire countries instead of only families within countries, why humans are so good at cooperating with co-ethnics, and why, as commenter Mugabe noted, the racially homogenous nations of first world Europe have more generous government benefits than the mixed race United States, where everyone is expected to pull themselves up by their bootstraps.

So how could ethnic altruism have evolved if the altruist allele decreases in frequency every time the altruist sacrifices his life?

Perhaps because it’s probably not determined by a single allele, but by a combination of many, many alleles, so every race, and sub-race, would have a natural level of group loyalty, that is normally distributed, with race traitors at one extreme of the bell curve, and race martyrs on the other. Thus every time a race martyr sacrifices his life for the group, the average level of racial loyalty within the group goes down maybe 0.00000000000001 standard deviation (SD) because the single race martyr has no kids, but the size of the group goes up by maybe 1%.

And since race martyrs are more likely to occur in races with a slightly higher average level of group loyalty, it would be those groups that would increase the most, thus increasing the average level of racial loyalty in the entire human species, even as it decreased slightly within groups.

Meanwhile, the opposite would happen in tribes low on race loyalty.  Every time a race traitor kills members of his own group to get access to more mates and food for himself and his kids, the level of race loyalty in the group goes down maybe 0.0000000000000001 SD, because a single race traitor had a lot of kids, but the size of group he belongs to goes down by maybe 1%.

And since race traitors are more likely to occur in groups with a low average level of group loyalty, those groups would gradually get smaller, and so the average racial loyalty of the entire human species would again increase.