ABSTRACT
Medical literature, as well as popular belief, attributes a variety of nervous and mental disorders to parental consanguinity. The traditional theory that marriage between close relatives gives rise to nervous and mental diseases in the offspring does not give due weight to the complexity of the whole problem. The peculiar psychosexual constitution which, according to S. Freud, forms the basis of the neuroses, is in itself the most important cause of intermarriage between close relatives. Only secondarily does such intermarriage constitute a detrimental factor by reinforcing the existing neurotic disposition. To put intermarriages between close relatives into proper perspective in relation to the phenomena met with in a study of the psychology of the neuroses, one has to consider them along with a number of other manifestations.
