This study addressed the argument that early child care constitutes a risk to children's social adaptation, and that for high-risk samples this effect depends on the security of the infant-mother attachment relationship. A longitudinal investigation of 135 first-born children in a low-risk sample was conducted to discern the contribution of child care experience and security of infant-mother attachment on child social competence at age 2.5 years. Detailed descriptions of the families' use of parental and nonparental care from birth to 2.5 years were obtained through parent interviews at infant-age 4, 12, and 30 months. Security of attachment was assessed in the Strange Situation procedure (M. Ainsworth and others) at 12 months. Children's levels of social interaction with adult carers and profiles of social adaptability with peers were derived from observational measures of peer play and child initiations to adults and peers while at play with a familiar peer group. Results suggested that for a low-risk, representative sample, attachment security and early experience of child care are not predictors of child social adaptability. Social interaction patterns in the play setting were most influenced by setting characteristics, including the quality of care, the presence or absence of the mother, the number of children, and by children's patterns of attendance. Contains 10 references. (Author)