PITUITARY-ADRENAL RESPONSE TO WEANING IN INFANT SQUIRREL-MONKEYS

This paper examines the pituitary-adrenal response of infant squirrel monkeys during the 2 weeks following the permanent removal from their mothers at the time of weaning in the laboratory. The influence of three major factors on the pituitary-adrenal response to weaning was studied: (1) preweaning experience with maternal separations; (2) familiarity with the postweaning environment; (3) preweaning social experience. The results indicated that prior separations lead to greater cortisol elevations than those observed in infants experiencing their first maternal separation at weaning. Those infants permitted to remain in their familiar social group displayed lower cortisol than did those in the novel cage alone. This was due to the social interactions and not to familiarity with the postweaning environment, since infants reared only with their mothers did not show this reduced cortisol elevation in their home environment.