[kowabungalow]

I think the problem is social tendency toward exaggeration and categorization. There are different social groups that have different but overlapping bell curves and whether it is nature or nurture is scientifically interesting, but dwelling on it all that much tends to get people hiring, marrying, grading, etc, based on the group instead of realizing a particular person will be somewhere on the curve and then kind of rewriting all of reality to fit the assumption that they really are nearer the average in their group than pesky reality keeps demonstrating.