Psychomotor and mental development from birth to age of four years; sex differences and their relation to home environment. Children in a new Stockholm suburb. Results from a longitudinal prospective study starting at the beginning of pregnancy.

Five hundred and thirty-two pregnant women were interviewed about their psychosocial health at the beginning of pregnancy. According to various factors including alcoholism, mental disease and criminality among the women and their husbands the families were divided in three groups of different degrees according to psychosocial stress. The pregnancies, deliveries and the 497 live-born children in these families have been investigated with prospective methods. Data concerning the psychological development and psychiatric health of the child were attained by interviewing the mother and evaluating the child during visits to home (age 1 and 4). The physical health and development of the children has been followed by prospective data achieved from the child welfare centers. At one year of age 452 of the children (226 boys, 226 girls) and at four-five years of age 412 of the children (202 boys, 210 girls) were evaluated by the Griffith's Development Scales. Findings from these evaluations can now be related to a number of factors concerning the psychosocial situation, pediatric riskfactors etc. With the prospective, longitudinal methods used in this project interesting results concerning sex differences related to the mental development have been found. At one year of age girls had higher scores than boys on the Griffiths-subscale measuring hearing-and-speech abilities. At four years of age several significant differences between the sexes were found. Girls had more "even" Griffiths-profiles and scored higher than boys in several Griffiths-subscales. The greatest differences at four years of age were found concerning personal-social function and eye-hand-coordination. Boys seem to be specially vulnerable to the psychosocial situation in their homes as the Griffiths-results at four years of age are lower among boys from homes with psychosocial stress compared to other boys. It should be very interesting to follow and study what these sex differences mean concerning future development, the occurrence of psychopathology school difficulties.