The author reviews the literature on twins, including Burlingham's concept that identification produces altruism and fairness as a reaction-formation against competition employed to overcome the twins' envy and jealousy of each other. Beckwett quotes Freud, 'anatomy becomes destiny', in the case of a little girl twin where identification and fairness are constantly interfered with and disproved by the difference in anatomy as well as by hereditary differences. The case is dramatic and beautifully written. The patient came into analysis at age thirty-seven after an incident during which she was paralyzed with fear that