Dominance and submissiveness between twins. II. Consequences for mental health.

In a follow-up study of 234 twin pairs, now aged 12-20 yrs, the intertwin relationships were evaluated by the parents and the twins themselves. The dominance-submissiveness aspect was inquired from three separate points of view, physical dominance, psychic dominance, and role of the spokesman. These three different aspects of dominance reflected on the twins' well being and mental health in somewhat different ways. The submissiveness in one area was often compensated by equality or dominance in another area, with only about 10% of adolescents being submissive or dominant in all three areas. According to the parents' reports, the most submissive twins suffered most often from psychosomatic symptoms, and the most dominant ones from nervous symptoms. The twins who themselves reported to be most submissive had most often somatic complaints and scored highest in the Kovacs' Depression Inventory.