Assessing the personality structure of wild capuchin monkeys (Sapajus xanthosternos) using trait rating and behavioral coding.

Abstract

The study of personality in nonhuman primates has increased substantially, but most studies so far have been conducted with captive animals. In addition, few studies investigated the personality of Neotropical (Platyrrhini) monkeys. If we aim at investigating the ecological and social significance of personality in nonhuman primates, conducting studies of wild populations and covering a wide range of taxa is essential. In this study, we analyzed the personality structure of a wild group of Neotropical monkeys, the yellow-breasted capuchin (Sapajus xanthosternos). We adopted two widespread methods: trait rating, using the Hominoid Personality Questionnaire, and behavioral coding, analyzing 13 behaviors and 3 derived variables. We described 3 traits with trait rating, labeled Openness–Neuroticism, Assertiveness, and Attentiveness–Sociability. We also described 3 traits with behavioral coding, labeled Prosociality, Aggressiveness, and Reactivity to Humans. Comparing both methods we found not only broad convergences between the structures obtained (e.g., both showed prosocial and aggressive traits) but also some differences (e.g., Openness–Neuroticism was not clearly defined with behavioral coding), concluding that combining both methods provided complementary findings. Some socioecological variables seem to influence the expression of personality in captive versus wild living monkeys. For example, in our study, assertive individuals were more vigilant, whereas in the studies in captivity, neurotic individuals were more vigilant. These questions highlight the need for more research in wild conditions and enlarging the number of species and populations studied.

A longitudinal assessment of behavioral development in wild capuchins: Personality is not established in the first 3 years

“…Empirical research for assessing personality usually relies on two methods: behavioral coding and trait rating (Gosling, 2001). However, there is considerable debate in the literature about the adequacy of each methodology (Fernández‐Bolaños, Delval, De Oliveira, & Izar, 2020; Vazire, Gosling, Dickey, & Schapiro, 2007). Behavioral coding is considered a time consuming way of assessing personality (Freeman, Gosling, & Schapiro, 2011).…”

“…Activity may not be a "true" personality trait, since capuchins adapt their levels of activity to environmental requirements (e.g., Izar et al, 2012), and perhaps not to consistent Visalberghi, 2016). The personality structure of these studies show clear convergences: the behavioral constructs arousability, impulsiveness, or anxiousness (Uher et al, 2013) fit with Neuroticism (Fernández-Bolaños et al, 2020;Manson & Perry, 2013;Morton et al, 2013b); the behavioral constructs "creativenessinventiveness" or "curiousness" (Uher et al, 2013) fit with Openness (Fernández-Bolaños et al, 2020;Manson & Perry, 2013;Morton et al, 2013b); the behavioral constructs "aggressiveness," "competitiveness," or "dominance" (Uher et al, 2013) fit with Assertiveness (Fernández-Bolaños et al, 2020;Morton et al, 2013b) or with Extroversion (Manson & Perry, 2013); and the behavioral constructs "social orientation to conspecifics" or "gregariousness,"…”

“…fit with Sociability (Fernández-Bolaños et al, 2020;Morton et al, 2013b) or with Agreeableness (Manson & Perry, 2013).…”

Personality, Subjective Well-Being, and the Serotonin 1a Receptor Gene in Common Marmosets (Callithrix jacchus)

“…These findings in common marmosets are remarkable in that, although many primate and non-primate species exhibit individual differences in these traits (24,25), the only other primate species in which they reflect the presence of one or two broad personality domains include chimpanzees Pan troglodytes (26)(27)(28)(29)(30)(31), bonobos Pan paniscus (17), and both brown Sapajus apella (32) and perhaps golden-bellied capuchin monkeys Sapajus xanthosternos (20), and humans Homo sapiens (e.g., 33). Cooperative breeding therefore appears to have led to the evolution of a domain that, until now, has only been found in larger brained primate species.…”

“…Pan (17), the genera Saimiri, Sapajus, and Cebus (18)(19)(20), and of Callitrichidae (21) indicate that species socioecology influences personality structure evolution. This appears to also be true for common marmosets, that is, cooperative breeding appears to have influence how personality traits are organized in this species.…”