Personality in captive killer whales (Orcinus orca): A rating approach based on the five-factor model.

Abstract

The comparative study of animal personality has received great interest in recent years. Some studies have analyzed personalities in cetaceans (exclusively in dolphins), but none have analyzed the factorial structure of personality of any species in this order. Our objective was to evaluate a sample of captive killer whales (n = 24) adapting one of the most widely used models of personality in humans and nonhuman animals: the five-factor model. A total of 38 personality descriptive adjectives were rated by 55 raters (mainly trainers and curators). Principal components analysis and regularized exploratory factor analysis revealed four statistically significant factors with acceptable standards of interrater reliability and validity, accounting for 49.85% of the variance. The first factor indicated an Extraversion factor, the second one revealed a combined factor of Conscientiousness and Agreeableness, the third one yielded in a Dominance factor, and the fourth one reflected a Careful factor very close to a combination of Conscientiousness and Agreeableness factor. The results were compared with the results obtained for humans and chimpanzees in prior studies. The similarities could be explained as a result of convergent adaptive traits despite a deep evolutionary divergence, adaptation to physically dissimilar environments, and very different neuroanatomical organization.

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

“…The regression method produces standardized component scores (i.e., with a mean equal to 0 and a variance equal to the squared multiple correlation between the estimated component scores and the true component values), and essentially predicts the “location” of each individual on the component, that is, the component score represents a composite score for each individual on a particular component (DiStefano et al, 2009; Field, 2018; Tabachnick & Fidell, 2013). Due to our relatively small sample size, we repeated all analyses with a regularized exploratory factor analysis (REFA), following procedure described in Úbeda et al (2019) and Úbeda and Llorente (2015). Namely, we used unweighted least squares and Quartimax rotation for factor extraction.…”

Personality structure in bottlenose dolphins (Tursiops truncatus).

“…Ciardelli et al also found a Reactivity/Undependability domain, which resembled the Human-directed Agreeableness domain that Gosling (1998) found in spotted hyenas ( Crocuta crocuta ). In another study, Úbeda et al (2019) found three domains—Extraversion, Dominance, and Conscien-agreeableness—in orcas ( Orcinus orca ), which resembled the domains found in California sea lions, 2 and a fourth domain, Careful, that was not found in California sea lions or in terrestrial mammals. Together, these studies of marine mammals suggest that personality domains like Dominance, Extraversion, and Reactivity/Undependability evolved in response to selective pressures other than those related to living on land, and that the evolution of the domain Careful may have been attributable to selective pressures unique to orcas or, perhaps, cetaceans in general.…”

“…Instead, in our preregistered analyses, we found that two cardinal markers of dominance ("Dominant" and "Submissive") were located between directedness and disagreeableness. These findings are unusual since strong dominance domains surface repeatedly in studies of nonhuman primates (Freeman & Gosling, 2010) and other species (Ciardelli et al, 2017;Gartner, 2014;Gartner & Weiss, 2013;Gosling & John, 1999;Jones & Gosling, 2005;Úbeda et al, 2019). Moreover, with the exception of an early study of personality in dogs that identified a factor labeled "emotion VI" (Cattell & Korth, 1973, pp.…”

Iberian Lynx (Lynx pardinus) personality: A rating assessment with ex Situ Conservation Program sample.

“…The total number of adjectives was 43, with a Likert rating scale of 1 to 7 (Likert, 1932). According to some of our previous studies (Úbeda & Llorente, 2015; Úbeda et al, 2019), we used the synonym-antonym evaluation, whereby the antonyms were deduced from the adjectives used in the previous studies (e.g., aggressive-pacifistic). Thus, according to the degree to which the adjective described the animal, the evaluation came closer to one pole or the other.…”