1Human Evolutionary Biology, Harvard University, 2Brain, Mind, and Behavior Unit, California National Primate Research Center, 3Psychology, University of California Davis
Friday 4:30-4:45, Ballroom B
Individual differences in stable behavioral phenotype (e.g. “personality,” “temperament,” “behavioral syndromes”) have been increasingly recognized to influence fitness parameters in numerous animal species, including humans and other primates. Our previous research suggested that infant macaques calibrate their behavioral phenotype to milk energy available from the mother; more milk energy predicted better coping and greater Confidence. We hypothesized that under conditions of limited milk energy, infants preferentially allocate energy to survival and growth rather than behavioral activity. Here we follow-up by investigating fitness outcomes as a function of behavioral phenotype among female rhesus in the outdoor breeding colony at the California National Primate Research Center from 2001-2009 (N=567). In infancy, subjects underwent a 25-hour standardized bio-behavioral assessment (BBA) to investigate responsivity to stressful challenges; measures included subjective temperament ratings and objective behavioral data. We constructed multiple regression models using AIC for model selection to analyze whether factor measures of behavioral phenotype predicted survival to reproductive maturity, growth, and age at first viable birth. None of the measures were associated with survival, however infants characterized as more ‘Gentle’ (temperament factor reflecting ratings of calm, flexible, curious, and gentle) had higher daily weight gain (p=0.014). Additionally females who displayed an active coping style during BBA as infants successfully produced their first viable infant at younger ages (p=0.05). Of particular importance, analyses controlled for maternal social rank. These results suggest that behavioral organization during early development has consequences for growth throughout juvenility and initiation of the reproductive career even in a well-fed captive population.
This research was funded by NSF BCS-0921978 (KH) and the NIH National Center for Research Resources (R24RR019970 [JPC], P51RR000169 [CNPRC]), and is currently supported by the Office of Research Infrastructure Programs/OD (R24OD010962 [JPC], P51OD011107 [CNPRC]).