Abstract
In this article, we discuss the concept of pivotal behavior and propose that this is a critical class of child behaviors that mediates the impact of parental responsiveness on children's development. To support this concept, we present data on 45 mother-child dyads which indicate that the level that children use pivotal behaviors is associated with the degree to which parents engage in responsive interactions with them. We also present data demonstrating several significant relationships between children's use of pivotal behaviors with their level of developmental functioning as assessed both by standardized assessments and play-based developmental observations. Finally, we propose the Pivotal Behavior Model of Developmental Learning. We argue that the impact that intervention has on children's development may be fundamentally dependent on whether procedures support and enhance key pivotal developmental behaviors.