Common marmoset (Callithrix jacchus) personality.

Abstract

Increasing evidence suggests that personality structure differs between species, but the evolutionary reasons for this variation are not fully understood. We built on earlier research on New World monkeys to further elucidate the evolution of personality structure in primates. We therefore examined personality in 100 family-reared adult common marmosets (Callithrix jacchus) from three colonies on a 60-item questionnaire. Principal components analyses revealed five domains that were largely similar to those found in a previous study on captive, ex-pet, or formerly laboratory-housed marmosets that were housed in a sanctuary.The interrater reliabilities of domain scores were consistent with the interrater reliabilities of domain scores found in other species, including humans. Four domains---conscientiousness, agreeableness, inquisitiveness, and assertiveness---resembled personality domains identified in other nonhuman primates. The remaining domain, patience, was specific to common marmosets. We used linear models to test for sex and age differences in the personality domains. Males were lower than females in patience, and this difference was smaller in older marmosets. Older marmosets were lower in inquisitiveness. Finally, older males and younger females had higher scores in agreeableness than younger males and older females. These findings suggest that cooperative breeding may have promoted the evolution of social cognition and influenced the structure of marmoset prosocial personality characteristics.

TheEGA+GNMframework: An integrative approach to modelling behavioural syndromes

“…Consistent with past research (Inoue‐Murayama et al., ; Iwanicki & Lehmann, ; Koski & Burkart, ; Koski et al., ; Šlipogor et al., ), we found moderate to large reaction norm intercept repeatability ( range: 0.33–0.91; see Figure a), providing evidence for personality across observational periods. As expected given our short focal sampling duration and observational methodology, which generally produce high observation–level variance (Martin & Suarez, ), long‐term ( range: 0.04–0.31) and short‐term ( range: 0.06–0.38) repeatability estimates were low to moderate.…”

“…The sociability and arousal clusters discovered here are well supported by and consistent with past marmoset personality research. In particular, the sociability cluster is consistent with the behavioural functions of the "Sociability" (Inoue-Murayama et al, 2018) and "Agreeableness" syndromes (Iwanicki & Lehmann, 2015;Koski et al, 2017) previously described with rating methods, while the arousal cluster is consistent with "Inquisitiveness" (Koski et al, 2017), "Openness" (Iwanicki & Lehmann, 2015), and the locomotor component of "Stress-Activity" (Šlipogor et al, 2016).…”

“…We now provide an empirical demonstration of the EGA+GNM framework using observational measures of social and arousal behaviours in a laboratory population of common marmosets (see Table 2). This empirical application serves as a comparison of Given past research demonstrating personality in similar marmoset behavioural traits (Inoue-Murayama, Yokoyama, Yamanashi, & Weiss, 2018;Iwanicki & Lehmann, 2015;Koski & Burkart, 2015;Koski et al, 2017;Šlipogor, Gunhold-de Oliveira, Tadić, Massen, & Bugnyar, 2016), we expected some degree of consistent amongindividual variation in these measures. We further hypothesized a priori a behavioural syndrome structure consisting of two latent factors causing sociability (contact sitting, allogrooming, and social proximity) and arousal (activity, scent-marking, and gnawing) behaviours to correlate.…”

How long does it take? Reliable personality assessment based on common behaviour in cotton-top tamarins (Saguinus oedipus)

“…A second set of behaviours defining cotton-top tamarin Extraversion included indices related to individuals' tendencies to explore their environment. In this way, tamarin Extraversion partly resembled common marmoset Inquisitiveness (Koski et al, 2017) and Openness dimensions (Iwanicki and Lehmann, 2015) identified by questionnaires (for details see Table S19), and…”

“…Confidence included dominance-related behaviours, low levels of scratching and indices connected to using the space and resources. Tamarin Confidence corresponded to the Assertiveness dimension in one ratings-based study of common marmosets (Koski et al, 2017).…”