A nonhuman primate model of risk for deviant development.

Delayed development and permanent retardation can result from genetic, prenatal, perinatal, and postnatal factors often acting through complex interactions. For human subjects experimental study of such developmental systems is often impossible due to confounding of variables and ethical considerations. One alternative is to study an animal model. A nonhuman primate model for studying genetic, physiological, and psychosocial processes producing delayed development was described in this paper. The model focuses on parental risk for poor reproductive outcomes using pigtailed monkey (Macaca nemestrina) subjects. In initial experiments subjects were offspring from high- and low-risk breeders who were nursery-reared with no postnatal contact with their parents. Results showed that both maternal and paternal factors are associated with delayed development in systems ranging from tooth eruption to concept learning ability.