A survey of 111 primitive societies reveals that circumcision rites occur more commonly in cultures where the son sleeps in the mother's bed as a child and the father sleeps in a separate hut. This evidence is taken to support Freud's suggestion that circumcision symbolizes the feared oedipal castration; the evidence is inconclusive, however, as it bears upon Bettelheim's idea that circumcision arises from men's envy of the vagina.