This symposium introduction outlines the first phase of an investigation of the mother-father-infant triad as an interactive system, influencing both parent attitudes and behaviors and child development. The focus of the research was on the early determinants of parental behavior. Subjects were 67 middle class, white parents and their first-born infants. Data were gathered during the prenatal, perinantal, and neonatal periods. Seven phases of data collection are described briefly, and the four papers to be presented from the study are previewed. The papers focus on: (1) the interactive system of the pregnant couple, (2) the relationships between the mother's adaptation to pregnancy and the labor and delivery experience, (3) the relationships between the infant's neonatal characteristics and the mother's self-image, and (4) the parent-offspring interaction in other species. (SDH)