This longitudinal study investigated mother-infant interaction patterns and infant social and emotional development as influenced by maternal and non-maternal infant care and by selected maternal and infant characteristics. Extensive data (including maternal attitude scores, demographic infomration, infant care observations, developmental test scores, stranger-approach responses, and separation behavior observations) were collected and analyzed for 181 mother-infant pairs at the infant's birth and 8 weeks, 3 months, 8 months, and 12-12 1/2 months later. Results showed that the employment status of the mother and the related use of non-maternal child care did not influence mother-child interaction patterns. The mother's caregiving behavior, attitudes, and role perception were found to affect infant social-emotional growth. Results of the study also showed some support for the existence in infants of a temperament-like behavioral style. Maternal attitudes reflecting beliefs in exclusive maternal caregiving and characteristics portraying infant-centered, adaptive approaches to child rearing showed considerable stability over the months of study. Interview instruments used in the study are reproduced in their entirety in the appendix. (Author/BRT)