ABSTRACT
Two strategies have evolved for studying the ontogeny of motivational, associative, and retentive mechanisms in altricial species. One is based on the view that altricial neonates are incompletely formed adults whose motivational, associative, and retentive capacities are likewise primitive. Differences between neonatal and adult performances are thus seen as quantitative only. The infant is thought to live in an overdetermined, protective environment that, through the mother and her nest, meets all its nutritional, hydrational, eliminative, and thermal needs. No environmental pressures are thought to foster either behavioral flexibility or concomitant associative development during the immediate perinatal period. As the neonate’s sensorimotor capabilities mature and it becomes increasingly liberated from mother and nest, so, too, “intellectual” capacities develop. Accordingly, at about the time of weaning or shortly thereafter the juvenile has caught up with and is essentially indistinguishable from the adult, as judged by its performance on a number of traditional animal-learning tasks—shock avoidance, for example. It follows therefore that a major task of this approach is to chart the course of adult development and to relate changes in performance to those in neurological and neurochemical ontogeny. The impressive progress attained through this approach has been documented by Campbell and Coulter (1976), and the most recent findings of a number of its leading advocates are admirably presented in the present volume.
