It was hypothesized that children, like adults, cognize social groups by applying social schemata. Their facility with social schemata was predicted to be a function of their level of cognitive development. When children were asked to complete partial social structures, formal and concrete operational, but not preoperational children, readily generated perfect structures. Particularly with concrete operations children, it was observed that the predisposition toward closure was stronger for vertical than horizontal structures. These results were interpreted with reference to the theory and observations of Piaget (1950). Implications for the understanding of the actual social groups of children were discussed. (Author)