There was once an almost entirely accepted scientific methodology for determining an individual's mental characteristics and personality traits by examination of the shape of his head - Phrenology, aka head bump reading. It is vaguely possible that the pseudoscientific separation of different breeding populations of Man into "races" through the visual examination of physical characteristics such as skin color, head and nose shape, hair type and so forth may have been valid when these populations were geographically isolated. However, because of centuries of interbreeding and geographic mobility, the justification (if there ever was one) for such differentiation has long since disappeared.