| Abstract: | We review data on aggression from psychological studies of offspring from two categories of abnormal prenatal sex hormone conditions: 1) endocrine disorders, and 2) hormone treatment during pregnancy. Both sources yield trends and some significant findings that are in line with the animal research based expectations of a positive androgen effect on the development of aggressive behavior. However, the available studies have many methodological weaknesses, and the results are not strong and open to interpretations by factors other than prenatal hormones. Potential modes of prenatal sex hormone effects are also discussed. In the second part, we present data on 13 boys and 15 girls who had been exposed to medroxyprogesterone acetate (MPA) in utero and on 28 closely pair-matched controls. The double-blind follow-up examination at age 9 to 14 years included questionnaires, half-structured interviews with mother and child separately, and a battery of psychological tests. Interviews were tape-recorded and rated by two independent raters. The results show weak but consistent differences, with the MPA-exposed subjects being lower in self- or mother-reported aggression than the controls. The results cannot be accounted for by differences in aggression-related rearing styles. However, the influence of pregnancy pathology cannot be totally excluded. We conclude that the available data are compatible with the hypothesis that prenatal sex hormones influence the development of human aggressive behavior. More sophisticated research studies are needed, however, to demonstrate hormonal effects and their mechanism of action in a reliable and valid fashion. |
