i want to add a caveat that the bit about race being fluid is a little bit cavalier, and should have probably come with some qualifiers. race is not necessarily fixed. race is potentially fluid. etc.

this is otherwise an excellent study.

but, you'll note that it isn't groundbreaking. the study itself points out that it's results are consistent with genetic testing and also with the anecdotal evidence that has come down to us orally.

http://aida.wss.yale.edu/~nq3/NANCYS_Yale_Website/resources/papers/NixQian_20150101.pdf