An axiom of every discussion you'll ever have is that all populations have exactly the same mean and standard deviation for every single measurable psychological trait that you can think of.
Which is all out wrong if you look at the literature. Nutrition, education, nurturing young, and inbreeding can have profound effects.
I suspect the person you replied to was being highly sarcastic in their reply. It's a highly charged area due to the history of race relations in the US.
Thanks, should have guessed, but I tend to assume the worst these days