In many American families today, no parent returns home from work until hours after the school day has ended. Some children attend formal afterschool programs during these hours or return home to a grandparent or other adult caregiver. During the elementary school years, however, children often begin to spend time after school on their own. Cain and Hofferth (1989) report that 2.4 million children in the United States regularly spend time unsupervised by adults or older teenagers, and that the percentage of children who are unsupervised increases steadily with age.

Children without adult supervision often arouse concern. During World War II, Zucker (1944) saw maladjustment and delinquency looming for “latchkey” children whose mothers sought wartime employment. “The house key tied around the neck is the symbol of cold meals, of a child neglected and shorn of the security of a mother's love and affection” (Zucker 1944, p. 43). As Medrich et al. (1982) observe: