This book examines the developmental functions of social pretend play (SPP), asserting that SPP is salient in the formation of both social interaction skills and friendships from the toddler period into middle childhood. Part 1 discusses the mastery of the communication of meaning in SPP and presents three studies on the relationship between mothers and toddlers in early symbolic play, the collaborative construction of SPP between toddler-age partners, and the differences and similarities between Mexican and American children's play dialogues. Part 2 focuses on issues of control and compromise by negotiating SPP meanings and scripts, presenting two studies on mothers' beliefs about mediating peer play and toddler-age children's peer networks and attachment security and SPP negotiations. Part 3 examines issues of trust and intimacy within SPP, presenting three studies on friendship and SPP, multiple attachments and peer relationships in SPP, and self-disclosure in the pretend play of physically and sexually abused children. (Contains approximately 225 references.) (MDM)