This paper describes a study of the socioemotional functioning of middle-class male and female preschoolers who had experienced varying degrees of nonparental care during the infant/toddler period. A review of the literature revealed that previous research findings from child care programs were inconclusive about potential differential effects on socioemotional development of participation in groups as a function of the child's sex. Three groups of preschoolers (105 preschoolers) from nine different child care centers participated in the study. Children in Group 1 had continuous, full-time, nonparental care that began prior to 9 months of age. Children in Group 2 had part-time, nonparental care that began prior to 9 months of age, and full-time nonparental care thereafter. Children in Group 3 had no full-time, nonparental care during the first 3 years of life, and had full-time nonparental care after the third year. Children's socioemotional behaviors were rated by teachers, and social interactions with peers and teachers were videotaped and coded. Mothers completed the Waters' Q-Sorts, which provide measures of child dependency and attachment. Results indicate that no differences between boys and girls could be attributed to differential effects of time of entry into child care. Appended are 28 references and a table of related material. (GLR)