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

Abstract

Animal personality is defined as consistent individual differences across time and situations, but little is known about how or when those differences are established during development. Likewise, several studies described the personality structure of adult capuchin monkeys, without assessing the ontogeny of these personality traits. We analyzed the behavioral repertoire of 12 wild infants (9 males, 3 females) yellowbreasted capuchin monkeys (Sapajus xanthosternos), in Una Biological Reserve (Bahia, Brazil). Each infant was observed and filmed weekly from birth until 36 months, through daily focal sampling. We analyzed the behavior of each individual in 10 developmental points. By means of component reduction (principal component analysis), we obtained four behavioral traits: Sociability, Anxiety, Openness, and Activity. We investigated whether there were developmental effects on those traits by fitting regression models for the effect of time on behavioral traits, controlling for monkey identity, sex, and cohort. Sociability (decreasing) and Anxiety (increasing) changed significantly along development. By means of repeatability analysis, we did not find intra-individual consistency across time in those traits, so we cannot discriminate stable personality traits in early ontogeny. Our results show that the personality structure of capuchin monkeys is not established during early development, in agreement with the literature on human personality.

Temporal consistency and ecological validity of personality structure in common marmosets (Callithrix jacchus): A unifying field and laboratory approach

“…Animal personality has been extensively researched in recent decades and described in many species, from invertebrates to humans (Freeman & Gosling, 2010; Gartner & Weiss, 2013; Koski, 2014; Kralj‐Fišer & Schuett, 2014; Réale et al, 2007; Weiss, 2018; Wilson et al, 2019). Personality has been linked with fitness (Adriaenssens & Johnsson, 2013; Seyfarth et al, 2012; Smith & Blumstein, 2008), development (Delval et al, 2020; Polverino et al, 2016; Stamps & Groothuis, 2010; von Borell et al, 2019; Wuerz & Krüger, 2015), longevity (Altschul et al, 2018; Careau et al, 2010), subjective well‐being (Gartner et al, 2016; Robinson et al, 2016; Weiss et al, 2009), choice of social partners (Ebenau et al, 2019; Massen & Koski, 2014; Verspeek et al, 2019), social information use (Carter et al, 2013; Carter et al, 2014a; Kurvers et al, 2010) and increasingly also cognition (Altschul et al, 2017; Dougherty & Guillette, 2018; Mazza et al, 2018), and genetics (Staes et al, 2019; Wilson et al, 2017).…”

Survey‐rated personality traits and experimentally measured coping style and stress reactivity, in wild baboons

“…Younger subjects were excluded from the study to avoid confounds attributable to personality growth trajectories (Clarke & Boinski, 1995; Suomi et al, 1996). That is, there are documented age‐related trajectories in personality and adult individuals exhibit more temporally stable personalities (Cabrera et al, 2021; Delval et al, 2020; Heath‐Lange et al, 1999; Sussman & Ha, 2011).…”

Desenvolvimento social de macacos-prego (Sapajus libidinosus) selvagens de 0 a 3 anos de idade

“…Isso poderia sugerir um efeito da mãe, porém, a Peteca, outra filha da Piaçava, não teve um tamanho de rede maior do que os outros indivíduos. Assim, um aumento de conexões com a idade poderia ser uma característica individual da Patrícia, relacionada ao temperamento social (Delval, Fernández-Bolaños, & Izar, 2020). Por outro lado, esse aumento nas redes de Patrícia pode também ser explicado pelo nascimento, dos infantes da segunda coorte que estavam em maioria presentes na sua rede no seus, vigésimo quarto e trigésimo sexto, meses de vida, Duca, Arizo, Marino, Peteca, assim como a infante Cenoura que nasceu entre a primeira e a segunda coorte e que não foi incluída neste trabalho.…”