Comparative Personality Assessment of Three Captive Primate Species: Macaca nigra, Macaca sylvanus, and Saimiri sciureus

Abstract

Comparative studies of primate personality offer informative insights into the evolutionary origins of personality structure in primate species. Primate personality research has, however, focused on a limited number of species. We investigated personality in three relatively understudied species: Sulawesi black crested macaques (Macaca nigra), Barbary macaques (Macaca sylvanus), and common squirrel monkeys (Saimiri sciureus). We sent a 38-item questionnaire to all European zoological institutions holding the study species and keepers were required to rate individuals on all items. Assessments achieved good levels of interrater reliability. Principal components analysis (PCA) revealed Sociability and Dominance personality dimensions in all study species, an Emotionality dimension in both M. nigra and M. sylvanus, a Cautiousness dimension in S. sciureus, and a Human-Animal Sociability dimension in M. sylvanus. Sociability and Dominance dimensions were shown to have good construct validity, as assessed through appropriate relationships with sex and age and correlations with behavioral measures. The Sociability, Dominance, Emotionality, and Cautiousness dimensions were comparable with analogous dimensions in other primate species but aggressive-type traits did not load onto the Dominance dimension in the two Macaca spp. We suggest that this may be attributed to their more tolerant social systems compared to those of other primate species. The Human-Animal Sociability dimension could not be compared with other primate studies as, to date, there has been limited Int J Primatol investigation of human-directed personality dimensions in captive primates. Our findings suggest that the two Macaca species are more similar to each other, in terms of their personality structure, than either is to S. sciureus, which suggests phylogenetic similarity is an important predictor of personality. However, further comparative analysis of a wider range of primate species is needed to inform theories regarding the evolution of primate personality structure.

Bonobo personality: Age and sex effects and links with behavior and dominance

“…However, animal personality is also measured using trait ratings, which involves asking humans familiar with individual animals to rate these animals on a set of predefined traits (Freeman and Gosling, 2010). This approach was at first perceived as 'subjective' and anthropomorphic by behavioral biologists, but very likely reflects real personality constructs so long as they meet the same criteria as behavioral observations and behavioral tests (Gosling and Vazire, 2002, Vazire et al, 2007, Weiss et al, 2012, Baker et al, 2015. The first criterion is that ratings have to be consistent across observers, different times of measurement, and different contexts (Capitanio, 1999, Dutton, 2008, King et al, 2008, Weiss et al, 2011.…”

“…The first criterion is that ratings have to be consistent across observers, different times of measurement, and different contexts (Capitanio, 1999, Dutton, 2008, King et al, 2008, Weiss et al, 2011. The second criterion is that the link between personality dimensions and life history parameters, such as sex and age, as well as between personality dimensions and other measures (typically behaviors) has to be established (Capitanio, 1999, Pederson et al, 2005, Uher and Asendorpf, 2008, Murray, 2011, Baker et al, 2015. If males and females face different selection pressures, sex differences in personality may emerge.…”

“…In addition to testing comparative validity by examining sex and age differences in personality, it is important to test for construct validity of the dimensions, by looking at how personality correlates with other measures in ways that are consistent with the meaning (and likely function) of these dimensions (Capitanio, 1999, Paunonen, 2003, Pederson et al, 2005, Uher and Asendorpf, 2008, Murray, 2011, Baker et al, 2015. One way to assess the construct validity of these ratings-based measures is to examine their correlations with naturally occurring behaviors (Pederson et al, 2005, Vazire et al, 2007, Konečná et al, 2008, Uher and Asendorpf, 2008 and/or behaviors in response to experimental tests (Baker et al, 2015, Carter et al, 2012.…”

“…One way to assess the construct validity of these ratings-based measures is to examine their correlations with naturally occurring behaviors (Pederson et al, 2005, Vazire et al, 2007, Konečná et al, 2008, Uher and Asendorpf, 2008 and/or behaviors in response to experimental tests (Baker et al, 2015, Carter et al, 2012. In behavioral tests stimuli are introduced to provoke behaviors that occur infrequently or that are difficult to observe in a naturalistic context.…”

“…For example, novel food/object tests or predator experiments have been used to assess novelty seeking and boldness in several species (Carere and Eens, 2005, Carter et al, 2012, Massen et al, 2013, Andersson et al, 2014, Baker et al, 2015.…”