This study was designed to: (1) obtain ecological data on the social behaviors of children in the preschool classroom especially in freeplay settings, and (2) identify characteristics of the physical environment and program variables which support, attenuate, or preclude social behaviors and social development. Observations were made of 16 3-, 4-, and 5-year-olds in many settings within a university laboratory preschool classroom over a period of 6 weeks, using a 7-category observation schedule. The schedule comprised social interactions, materials interactions, both social and materials interactions, and no interaction; each of the interactions was also judged positive or negative. In general, it was found that environmental supports (activities or equipment) which might have set the occasion for, and strengthened social behavior were not available. High levels of social behavior, however, occurred in areas where there was an ample supply of materials and no apparent "need" to interact. The results of this study suggest that the rate of social behavior was low. At best, the level of social behavior was more comparable to that of younger children. When social behaviors occurred, their distribution among the settings was consistent with data obtained in samples having higher overall rates of social interaction. (GO)