[Problems in the assortedness of marriages in mental retardation].

The study of the educational and intellectual status of the parents of 402 oligophrenic patients revealed a high degree of marital homogeneity in the parents with regard to their intellectual development as compared to the control group of healthy subjects (419 families). The tendency to intellectual homogeneity was especially high in the parents of patients with undifferentiated forms of oligophrenia. It was also elicited that the educational and intellectual status in the oligophrenic siblings was significantly lower than in the control siblings which may be explained by genetic, cultural and familial factors.