Whereas Stoller talks about “gender identity,” Money and the Hampsons refer to “psychosexual orientation”: the meaning of both terms is the sense an individual has of himself or herself as male or female, of belonging to one or the other group. The development of this sense is essentially the same for both biologically normal and abnormal individuals, but the study of the

biologically abnormal can tell us a great deal about the relative parts played by biology and social rearing; there are a multitude of ways in which it can illuminate the debate about the origin of sex differences.