[The clinical picture and psychopathology of the XYY constitution].

It is reported on 2 cases of the XYY chormosomal constitution. The patients were comparable only with respect to some somatic deviations. Age at manifestation of psychic abnormalities as well as the degree of deviation of behaviour were rather different. One patient got his psychic traumatization mainly in early childhood where as the other suffered from a more puberal conflict. Genetic disposition may be the basic cause of the psychological abnormalities. Yet, the degree of deviation seems to be influenced mainly by environmental factors.