The human condition is, by almost any definition, exceptionally complex. Although we remain amazed at the range of individual differences that distinguish each and every one of us from the others, one of the purposes central to the human sciences has been the generation of laws and theories to describe the common features of human existence. It seems as though those of us who try to understand the human condition must struggle to deal with the tension that exists between trying to describe, explain, measure, and predict the common attributes of human beings on the one hand and appreciating and accounting for idiosyncratic individual differences on the other.