chapter  18
9 Pages

Sensori-motor differences

There has never been any real disagreement about genetically determined physical differences - biochemical, physiological, and anatomical-between racial groups. It is in the realm of intellectual functions that we see so much a priori resistance to rejection of the null hypothesis concerning genetic racial differences. But actually there is a continuum between the physical and the intellectual; there are no discernible discontinuities; and racial differences are found at all points along the continuum going from strictly physical characteristics to behavioral characteristics, including those processes we identify as mental ability. So the point at which one draws the line of resistance to entertaining a genetic hypothesis of racial differences is usually quite arbitrary.