A few days ago I posted a picture depicting the genetic ancestry of African-Americans modelled as a linear combination of European and Nigerian genetic clusters (reproduced below). Dienekes has some thoughtful comments on the same picture.
Meanwhile, Razib comments on a post from Ed Yong discussing the social flexibility of race. Ed cites a survey showing that people change their self-described race with surprising frequency, with about one in five respondents changing their description at least once over a nineteen year period (with some intriguing correlations with incarceration and employment status). Razib responds that the ability to “change” race is still contingent on biology; individuals with strong African ancestry are unable to readily pass themselves off as white.
It would be intriguing to quantitate this, by plotting genetic ancestry (as shown below) against the frequency of altering one’s self-reported ancestry from year to year. Following Razib’s argument, most African-American individuals clustering nearing the Nigerian end of the spectrum would be highly constrained as self-reported “black”; the further away from that end of the spectrum, the more freedom individuals would have to alter their racial identity to fit their social circumstances.
It would also be interesting to compare the effects of overall genomic ancestry with the impact of the comparatively small number of variants that determine racially salient features such as skin pigmentation; these would obviously be expected to have the largest impact on constraining self-described race.
Have similar studies already been done, perhaps using phenotypic markers rather than genetics? I’m completely ignorant about this area.