Pituitary-adrenal response to separation in mother and infant squirrel monkeys

Pituitary-adrenal response in mother and infant squirrel monkeys following brief separation was assessed. Each mother and infant pair was tested under each of 3 conditions: (1) Basal; (2) Separation-Reunion; and (3) Separation. Samples were obtained from mothers and infants in the Separation and Separation-Reunion conditions 30 min following the initial disturbance. A similar paradigm was used to assess the effects of separation in surrogate-reared animals. The results indicate that mothers, infants, and surrogate-reared infants respond to 30-min separation with a substantial increase in plasma cortisol. The values obtained in the Separation-Reunion condition did not differ significantly from Basal values in any of the 3 groups, suggesting that the effect of separation on the pituitary-adrenal system is not due to the disturbance involved in the separation procedure. The response of surrogate-reared infants suggests that these infants develop similar attachments to the surrogate as normal infants to their own mothers.