Lynn Fairbanks: UCLA

There has been considerable interest in gestational and neonatal influences on developmental trajectories in humans and other mammals in recent years. This presentation reviews results from the Vervet Research Colony demonstrating effects of maternal condition, diet and weight loss on maternal and infant behavior. To understand the impact of variation in maternal investment on development, it is important to recognize that infants are not simply the passive recipients of variation in maternal care. Mothers and infants adjust their behavior in relationship to one another, with the mother responding to her own condition, and the infant trying to counteract attempts to limit maternal care.
Longitudinal effects of maternal condition on juvenile behavior are then examined from contrasting theoretical perspectives, including developmental canalization, fetal programming, resilience, and stress inoculation theories. Results suggest that behavioral development is largely resilient to developmental challenges within an expectable range of experience. They provide support for stress inoculation theory in that juveniles who experienced higher levels of early maternal rejection as infants became more active promoters of their own social development, while the inhibitory effects of adverse early experience on juvenile behavior were more evident under novel and challenging circumstances. The results are consistent with the view that infant and juvenile behavior evolved in the context of variation in maternal care, and selection has favored strategies for immature offspring to get what they need for physical and social development.