This report discusses an empirical investigation of the social networks of German children in their first 5 years of life; particular attention is given to the frequency and the function of the child's social contacts with persons in his or her social environment. Data were collected by means of a questionnaire from 1033 families residing in 18 communities within North-Rhine Westfalia. Socialization functions investigated included protection, nursing or tending, emotional involvement, play, and instruction or teaching. Results suggest that children's social development can be characterized by five basic factors: (1) expansion of the social environment; (2) social segregation; (3) quantitative re-weighting; (4) qualitative changes in the function of social interactions, and (5) the child's coping strategies in reaction to social requirements. Results further indicate that relaxing the close mother-child relationship is a most important prerequisite for the child's progress in social development. The importance of the paternal function increases with the increasing age of the child, and paternal engagement with the child advances as a function of social class and degree of urbanization. The father-child relationship is subject to highly important changes which decisively influence and differentiate the conditions of social development under which children currently grow up. (RH)