Assessing Eysenck’s PEN model to describe personality in chimpanzees

• Published in: Behavioural processes 2023-08, Vol.210, p.104909-104909, Article 104909
• Main Authors: Padrell, Maria, Amici, Federica, Úbeda, Yulán, Llorente, Miquel
• Format: Article
• Language: English
• Subjects: Chimpanzees; Eysenck; PEN model; Personality; Questionnaires
• ISSN: 0376-6357; 1872-8308
• DOI: 10.1016/j.beproc.2023.104909

Questionnaires based on human models can be used to reliably assess personality also in non-human primates. In this study, we used an adapted version of Eysenck’s Psychoticism-Extraversion-Neuroticism (PEN) model that focuses on three higher-order personality traits. Extending previous work on a small group of chimpanzees (Pan troglodytes), we tested 37 chimpanzees housed at Fundació Mona (Girona, Spain) and the Leipzig Zoo (Germany). We assessed personality with a 12-item questionnaire, which raters scored using a 7-point Likert scale. To identify the personality traits, we conducted data reduction with Principal Components Analysis and Robust Unweighted Least Squares. The ICCs for the single (3, 1) and average (3, k) ratings indicated substantial agreement between raters. Parallel analyses identified two factors to retain, whereas the scree plot inspection and eigenvalues larger than one rule identified three factors. Factor 1 and 2 in our study were identical to the ones previously described for this species (labelled Extraversion and Neuropsychoticism, respectively) and we also obtained a third factor that could be related to Dominance (Fearless Dominance). Thus, our results confirm the potential of the PEN model to describe chimpanzee personality structure. •Eysenck´s PEN model is an effective way to reliably assess chimpanzee personality.•Principal Component Analysis and Robust Unweighted Least Squares factor analysis revealed 3 factors.•The factors were labelled Extraversion, Neuropsychoticism and Fearless Dominance.•Neuropsychoticism included aspects of human Neuroticism and Psychoticism.