One of the basic HBD-theories is the Cad-Dad-theory. The general idea is that in societies where women are dependent on a male provider to raise children successfully to adulthood, people evolve over time to have stable longterm relationships. Generally it is evolutionarily advantageous for men to just move on to the next fertile woman once a lover is pregnant, but this is not a behavior favored by evolution if it means your children will die. So men evolve to be dads.
This is supposed to have happened in European peoples because for a couple of thousand years plowing was work that required a man’s strength, so women and their children generally depended on a male provider. In Africa however, horticulture was and is the norm, i.e. cultivating gardens with a hoe, not a plow. This was and still is to a large degree women’s work. So in Africa women had the ability to provide for their children on their own. According to the theory, African men consequently stayed „cads“. Random internet dictionary: „an ill-bred man, especially one who behaves in a dishonorable or irresponsible way towards women.
This theory is then used to explain the high rates of single motherhood in African Americans, which is somewhere in the vicinity of 75% and the low rate of marriage. Now for all I know, this theory might well be completely correct. But in this blogpost I want to point out, that African Americans are certainly not a good choice to prove the correctness of the theory or gauge the size of this trait difference, for two simple reasons:
As we know, African Americans average 15 IQ points below the white mean and have the correspondingly lower socio-economic status. If you would control for these factors, the difference between whites and blacks in single motherhood or stable relationships would certainly shrink significantly. The difference attributable to IQ and SES differences cannot at the same time be attributed to some evolved character trait.
Additionally, and maybe even more importantly, the sex ratio of the African American community is severely skewed. This is mostly due to the fact the young African American men are quite likely to get shot or to go to jail (for example for shooting another African American man). In the fertile age range the ratio of women to men in the African American community is something like 130:100. This oversupply of women leads to significantly worse treatment of women and less stable relationships as has been shown for example by using the local variation in sex ratio in Chinese municipalities.
If you control for these two factors I wonder how much of the discrepancy would still remain.