TYMPANIC TEMPERATURE ASYMMETRY AND STRESS BEHAVIOR IN RHESUS MACAQUESAND CHILDREN

Objectives: To examine left-to-right tympanic membrane temperature asy mmetries and their possible association with biobehavioral stress resp onses in rhesus macaques and children. Subjects and Design: Infrared t ympanic membrane thermometry was completed bilaterally in 19 two-year- old rhesus macaques and 18 eight-year-old children in a cross-sectiona l, laboratory-based study. Unidirectional temperature gradients were c alculated as the mean of two left-sided measurements minus the mean of two right-sided measurements. Biobehavioral stress responses were ass essed in monkeys as agitated motor activity and adrenocortical activat ion after separation from the social group, and in children as parent- reported resilience to psychological stress and child behavior problem s. Results: Significant asymmetry was detected in tympanic membrane te mperatures in both monkey and child samples, with left-sided temperatu res measuring slightly but significantly higher than those from the ri ght tympanic membrane. Higher-magnitude left-to-right temperature grad ients were associated with stress-related locomotion in macaques and w ith lower resilience and more behavior problems in children. Conclusio ns: There are small but reliable asymmetries in the tympanic membrane temperatures of young human and nonhuman primates. Tympanic membrane t emperature gradients reflect important individual differences in biolo gically derived responses to psychological stressors.