Alien abductions and U.F.Ology are more like esoteric, transcendental experiences than physical occurances, even though there seems to be a lot more sexual and probing experiences in what has been reported the last thirty years.
Well, anyhow, the U.F.O cults are somewhat racist. Not in the sense of racial hatreds, but in explaining race as kind of genetic engineering experiences. Whether its a black U.F.O cult which believes the black and brown people as the true ‘original’ earthly races, and white people as the genetically engineered ones— or the white cults, which sometimes hold that white people are related to or descended from Nordic / Pleiadian aliens — the basic idea is that white people are the aliens or engineered race. There is often also the view that there are Reptilian aliens that have mixed with the bloodlines of European royalty or certain world leaders. So I guess that is why they are concerned with the bodies and earthly adaptation and reproductive capabilities of white people on the earth,
Grey aliens seem more concerned with taking FROM human stock to make Grey Alien / Human hybrids rather than infusing INTO the human race and becoming white people.
So, I would guess, that people who believe in these things probably believe that white people have alien DNA or blood, and that the Asian, Native American, and African races are more like the original, unmodified earthlings. U.F.O groups tend to be white and preoccupied with race and genetics.