Abstract— Although the developmental literature often mentions children’s trajectories, it has largely ignored the parent–child processes involved. This article presents a conceptual framework for investigating both parent and child roles. It theorizes that parents have 4 fundamental tasks: initiating trajectories, supporting development along trajectories, mediating children’s understanding of experiences, and reacting to child-initiated trajectories. Children’s roles include accepting or rejecting the pathways, engaging in them with varying degrees of enthusiasm, and initiating trajectories. The article discusses examples of cultural, familial, and relationship variables that influence trajectories. Effective parents initially guide their children’s trajectories in positive directions, although with development, guidance decreases in favor of the child’s increasing autonomy. This model helps to reveal some of the dynamic interactional processes that contribute to certain developmental outcomes.