This project focuses on long-term consequences of individual differences in physical, social, and affective functioning and the description of early interactions in diverse ecological contexts. Extensive observations of infant-mother interaction and attachment in infants from upper-middle class Euro-Americans and lower-class Central American families revealed that, regardless of social or ethnic background, mothers spent comparable amounts of time in discrete activities such as feeding, caring for, and playing with their infants. Systematic analyses demonstrated that the quality of social interaction within dyads changed dramatically depending on the functional and social context. As a result, extended observations were necessary to obtain reliable indices of individual differences. Similar findings were obtained in a study of Costa Rican mothers and infants from lower and middle income backgrounds. Comparable day-long observations of mothers and infants in Quebec, Germany, the Central African Republic, and Colombia were conducted to further explore the effects of culture and context on early interactions and these data are currently being analyzed. We hope that systematic and detailed observations of parents and infants in a variety of ecological contexts will provide a clearer understanding of the content to which infant experiences vary and of the best ways of obtaining reliable indices of individual differences within cultures.