This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Maternal behavior in primates is a complex process, involving a number of physiological and life history variables. This study is the first to include behavioral, life history, endocrine, and genetic data from a large number of nonhuman primate subjects in the determination of factors related to maternal behavior. The project will increase our knowledge of the heritable nature of variation in maternal behavior, will characterize mothers with poor maternal qualities, and will provide information useful for selecting females used in breeding programs. This project generates behavioral and hormonal profiles to be used in the development of the baboon as a model of maternal behavior by quantifying mother-infant interactions, determining infant outcome, and measuring hormone levels in a large sample of captive baboons. It will then examine the causes of variation in maternal behavior, including hormonal, experiential, and genetic factors. It is expected that the information resulting from this study will lead to new avenues of research on the mechanisms involved in the regulation of maternal behavior, as will as providing a model for related studies in reproductive endocrinology, colony management and behavioral research. During the course of this project, behavioral and endocrinological data have been collected from more than 300 baboon mothers. Most of these mothers have been observed during one pregnancy and the subsequent rearing of that one infant, but more than 25 subjects have provided information on their behavior toward two infants.