One thing I would be curious about is how members of the same race treat each other. Do black people favour black people the same way white people favour white people?
Anecdotal but in Asia, white features are in "high" demand. One of the most popular surgeries in Korea is lifting the eyelids higher to look more Caucasian.
I was hoping for statistics, not anectotes. Like P(got a match|caucasian) vs P(got a match|latino) or similar.
For that, there's the OKCupid blog post mentioned in the article[0] or the book that covers the same ground[1].