Abstract
The double standard of extramarital sex and the near universal restriction upon extramarital sex for wives are examined. The double standard is in terpreted as a reflection of both male fears of sexual betrayal and male concern over sexual adequacy. Each of these dispositions is in turn traced to a different and independent child training antecedent. Restrictive norms for wives are explained in terms of the sociobiological paradigm. Extra marital sex norms are examined in relation to other sexual attitudes and practices.