Fascinating. So, race is the small issue. Equality is the large one. People get offended or defensive about race because of the implication or possibility of implication of inequalities, the primary principle. Otherwise, they're usually pretty cool talking race stuff. But it's always guarded. Just don't cross that sacrosanct equality barrier, or its hate, not talk. Physiology (esp. sexes) and psychometrics is a better way to Sun Tzu the less guarded flanks. Race is an expected frontal assault on equality.