The idea of reincarnation is presented as having considerable explanatory value for several features of human personality and biology that currently accepted theories do not adequately clarify. Reincarnation is not offered as a substitute for present knowledge derived from genetics and understanding of environmental influences; it may, however, usefully supplement such knowledge. The present paper does not present evidence from cases suggestive of reincarnation. It does, however, cite cases of subjects who have claimed to remember previous lives, most of whose statements have been verified in the course of detailed investigations. For each case, a reference is provided to a detailed published case report furnishing the evidence in that case. The idea of reincarnation may contribute to an improved understanding of such diverse matters as: phobias and philias of childhood; skills not learned in early life; abnormalities of child-parent relationships; vendettas and bellicose nationalism; childhood sexuality and gender identity confusion; birthmarks, congenital deformities, and internal diseases; differences between members of monozygotic twin pairs; and abnormal appetites during pregnancy. Empirical studies of cases of the reincarnation type have so far not provided any evidence that justifies using reincarnation as an explanation for the occurrence of child prodigies of the large inequities in socioeconomic conditions of humans at birth.