In this article we focus on a major advance of the past few decades: the introduction of mental representation as a tool for understanding social development. We argue that despite the considerable contributions made by this approach, it is underrepresented in social developmental research, except in the area of attachment. We go on to show that mental representations (1) play a key role in the social and self-related outcomes researchers value most highly, (2) are the carriers of socialization experience and a major means through which experience affects children?s outcomes, (3) have unique implications for pinpointing important socialization practices and designing effective interventions, and (4) can link social development to other areas in psychology. We also suggest, along with other recent authors, that mental representations hold the key to understanding the important issue of continuity and change in development.