title: Environmental control, social context, and individual differences in behavioral and cortisol responses to novelty in infant rhesus monkeys.
abstract: The effects of appetitive controllability on behavioral and cortisol reactivity to novelty in 12 infant rhesus monkeys were studied. Surrogate-peer-reared infants had homecage access to food treats contingently via lever pressing ("master") or noncontingently ("yoked") for 12 weeks from postnatal month 2. Masters lever-pressed more, but did not differ in baseline cortisol. At month 5, infants were exposed to a novel environment in social groups and individually. Masters were significantly more active and exhibited significantly lower cortisol reactivity to the novel environment, but only in the individual context. Also, individual differences in operant behavior were positively correlated with behavioral activity and negatively correlated with cortisol reactivity to the novel environment. The results reveal context-specific benefits of contingent stimulation in infancy.
authors.affiliation: National Institute of Child Health and Human Development, USA. PeteRoma@gmail.com
authors.forename: Peter G
authors.initials: PG
authors.lastname: Roma
authors.forename: Maribeth
authors.initials: M
authors.lastname: Champoux
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Suomi
mesh_terms: D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn / Q000523:psychology*; D001070:Appetitive Behavior / Q000502:physiology*; D001143:Arousal / Q000502:physiology*; D005260:Female; D006854:Hydrocortisone / Q000097:blood*; D007030:Hypothalamo-Hypophyseal System / Q000502:physiology; D007206:Individuality; D007389:Internal-External Control; D008253:Macaca mulatta / Q000523:psychology*; D008297:Male; D008426:Maternal Deprivation; D010913:Pituitary-Adrenal System / Q000502:physiology; D012919:Social Behavior; D012931:Social Environment; D013223:Statistics as Topic
chemical_list: D006854:Hydrocortisone