Social responsiveness, reacting in a socially engaged way to the actions of others, is a fundamental characteristic of infant behavior and contributes to the type and quality of social interaction infants experience. Early social interactions play an important role in supporting emotional, cognitive, and language development. Even prenatal experience can influence infants' later development. For example, hearing mothers' speech late in pregnancy enables infants to recognize their native language immediately after birth. However, there has been little research to date regarding how prenatal experience contributes to the development of infant social motivation, social learning, or social memory. The primary goal of this project is to investigate how maternal behaviors during the prenatal period contribute to social motivation, social recognition, and social learning and memory after birth. Ethical considerations limit opportunities to conduct experimental research on prenatal experience. A comparative approach using animal models helps to bridge this gap. In contrast to mammals where the prenatal environment is difficult to access and manipulate, the avian egg environment can be experimentally manipulated independent of the mother and thereby provides an excellent animal model for testing predictions about prenatal factors underlying subsequent postnatal development. This project will compare quail chicks who received typical patterns of prenatal experience with chicks who received modified maternally derived prenatal experience. The central hypothesis is that maternally regulated prenatal sensory stimulation, concentrations of hormones of maternal origin in the prenatal environment, and amounts of prenatal movement and light exposure contribute to the development of infant social responsiveness. The findings of this project will provide a foundation for a better understanding of the links between prenatal experience and postnatal behavior, and will inform research directions for human-based studies of early social development.