There are hereditary differences among human beings. Some of these differences have geographical correlates. Some genetic variants that produce physical or behavioral deficits occur significantly more often in some areas, or in some ethnic groups, than in others. However, none of these facts provides any intellectual support for the race concept, for racial classifications, or for social hierarchies based on ethnic-group membership.
The geographical element of the race concept is important in theory but is widely ignored in practice since it does not conform well to the facts of current human phenotype distribution. Much of the literature on supposed racial differences involves such geographically meaningless exercises as studying differences among "races" by subdividing a sample of North Americans. If races are defined as geographically delimited conspecific populations characterized by distinctive regional phenotypes, then human races do not exist now and have not existed for centuries,