In terms of muscle density, black people are the first, white people are the second and yellow people are the third, which is why black people are dominant in track and field or boxing, but because of this, black people can't be seen in swimming events.

In terms of heat resistance, black skin and hair have good radiation resistance. White people's high nose can warm the inhaled air, and their skin can absorb the heat of sunlight well, which is suitable for living in high latitudes. Yellow people are in between (except Eskimos).

Judging from the gray matter layer area of the brain, if the gray matter layer of white people is 100%, black people are only 80%, while yellow people can reach 1 10%.