The middle childhood years are characterized by numerous biological, psychological, and social changes (Eccles, 1999). During this period, children master fundamental academic skills such as reading and arithmetic and they also become more self-aware, reflective, and planful. Erikson (1968) characterized this phase of life as a time of “industry,” with attention directed at gaining competencies in a variety of tasks and learning how to cooperate with peers and adults. In contrast to children's very early years, when the influence of proximal family contexts is paramount, the middle childhood years represent a time of increasing influences of out-of-home environments. Although the family remains important for children's well-being, children at this age increasingly participate in organized programs and interact with peers in their community or neighborhood; they are also more influenced by teachers, school environments, and peer groups.

Low-income children face several challenges to successful development during this stage of life, and some of these challenges stem from the limitations or outright dangers inherent in their out-of-home environments (Leventhal & Brooks-Gunn, 2000). Physically dangerous neighborhoods (i.e., those in which children experience high levels of victimization) may force children to be isolated in their homes, restricting opportunities for interactions with peers and adults. Less-advantaged neighborhoods also provide fewer enriching opportunities such as parks, libraries, and children's programs.

Just as high quality child care opportunities can boost the development of young children in poverty, researchers have suggested that high quality out-of-school programs can augment the development of children during middle childhood.