Personality, happiness, and health in gibbons

Gibbons (family Hylobatidae) are small apes comprising lar gibbons (Hylobates spp.), crested gibbons (Nomascus spp.), siamangs (Symphalangus syndactus), and hoolocks (Hoolock spp.). These four genera are closely related to one another and to orangutans (Pongo spp.). Gibbon phylogeny and socioecology make them uniquely suited to improve our understanding of the origins of personality factors. Personality trait ratings of lar gibbons, crested gibbons, and siamangs-sufficient data on hoolocks were not available-were analyzed using exploratory factor analyses. All three genera possessed factors labeled Dominance, Extraversion, and Agreeableness. In addition, lar gibbons and siamangs possessed factors labeled Neuroticism and Conscientiousness, lar gibbons possessed a factor labeled Individualism, and crested gibbons possessed factors labeled Dyscontrol and Avoidance. Exploratory factor analysis of the combined data, which included hoolocks, revealed a Conscientiousness factor and four factors-Extraversion, Dominance, Agreeableness, and Neuroticism-that resembled four of the five orangutan personality factors. Genus- and family-level analyses revealed that better subjective well-being and health-both measured using informant ratings-were associated with higher sociability, emotional stability, and conscientiousness. Based on these results, we concluded that social group size and/or arboreality are related to factor structure, Conscientiousness evolved in hominoids 16-20 million years ago (much earlier than previous estimates), and that relationships in humans between personality and psychological and physical well-being have very early origins. (PsycInfo Database Record (c) 2026 APA, all rights reserved).