title: Personality Traits in Rhesus Macaques (Macaca mulatta) Are Heritable but Do Not Predict Reproductive Output.
abstract: There is growing evidence that behavioral tendencies, or "personalities," in animals are an important aspect of their biology, yet their evolutionary basis is poorly understood. Specifically, how individual variation in personality arises and is subsequently maintained by selection remains unclear. To address this gap, studies of personality require explicit incorporation of genetic information. Here, we explored the genetic basis of personality in rhesus macaques by determining the heritability of personality components and by examining the fitness consequences of those components. We collected observational data for 108 adult females living in three social groups in a free-ranging population via focal animal sampling. We applied principal component analysis to nine spontaneously occurring behaviors and identified six putative personality components, which we named Meek, Bold, Aggressive, Passive, Loner, and Nervous. All components were repeatable and heritable, with heritability estimates ranging from 0.14 to 0.35. We found no evidence of an association with reproductive output, measured either by infant survival or by interbirth interval, for any of the personality components. This finding suggests either that personality does not have fitness-related consequences in this population or that selection has acted to reduce fitness-associated variation in personality.
authors.affiliation: Duke Institute for Brain Sciences and Center for Cognitive Neuroscience, Duke University, Durham, North Carolina 27708; and Centre for Research in Evolutionary and Environmental Anthropology, University of Roehampton, London, U.K.
authors.forename: Lauren J N
authors.initials: LJ
authors.lastname: Brent
authors.affiliation: Centre for Research in Evolutionary and Environmental Anthropology, University of Roehampton, London, U.K.
authors.forename: Stuart
authors.initials: S
authors.lastname: Semple
authors.affiliation: Centre for Research in Evolutionary and Environmental Anthropology, University of Roehampton, London, U.K.
authors.forename: Ann
authors.initials: A
authors.lastname: Maclarnon
authors.affiliation: Caribbean Primate Research Center, University of Puerto Rico, Medical Sciences Campus, Punta Santiago, PR.
authors.forename: Angelina
authors.initials: A
authors.lastname: Ruiz-Lambides
authors.affiliation: Caribbean Primate Research Center, University of Puerto Rico, Medical Sciences Campus, Punta Santiago, PR.
authors.forename: Janis
authors.initials: J
authors.lastname: Gonzalez-Martinez
authors.affiliation: Duke Institute for Brain Sciences and Center for Cognitive Neuroscience; and Departments of Neurobiology, Evolutionary Anthropology, and Psychology & Neuroscience, Duke University, Durham, North Carolina 27708.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Platt
keywords: Additive genetic variance; Behavioral tendencies; Fitness; Quantitative genetics; Reproductive success