Berreby's First Law
Human kinds exist only in human minds.
Human differences and human similarities are infinite, therefore any assortment of people can be grouped together according to a shared trait or divided according to unshared traits. Our borders of race, ethnicity, nation, religion, class etc. are not, then, facts about the world. They are facts about belief. We should look at minds, not kinds, if we want to understand this phenomenon.
Berreby's Second Law
Science which seems to confirm human-kind beliefs is always welcome; science that undermines human-kind belief is always unpopular.
To put it more cynically, if your work lets people believe there are "Jewish genes'" (never mind that the same genes are found in Palestinians) or that criminals have different kinds of brains from regular people (never mind that regular people get arrested all the time), or that your ancestors 5,000 years ago lived in the same neck of the woods as you (never mind the whereabouts of all your other ancestors), well then, good press will be yours. On the other hand, if your work shows how thoroughly perceptions of race, ethnicity, and other traits change with circumstances, well, good luck. Common sense will defend itself against science.