Personality in two communities of wild chimpanzees

Studies of captive chimpanzees have revealed six latent variables (factors) account for individual variation in large numbers of traits. These factors include Dominance, and five further factors—Extraversion, Conscientiousness, Agreeableness, Neuroticism, and Openness—that resemble personality factors found in human societies. A study of personality among chimpanzees who lived or were living in Gombe National Park, Tanzania, however, did not find these factors. One possible explanation for this finding was that, by necessity, a brief version of the Hominoid Personality Questionnaire was used. The present study tested this possibility in 40 chimpanzees in Budongo Park, Uganda. These chimpanzees belonged to either the Sonso or Waibira community. Seven field workers and researchers provided ratings using the Hominoid Personality Questionnaire (HPQ) such that each chimpanzee was rated by an average of 3.875 raters. A total of 46 of the 54 items showed evidence of interrater reliability. We used a regularized exploratory factor analysis to extract factors from 39 items (the maximum possible for the sample size). These factors were identifiable as those found in other studies of chimpanzees. These preliminary findings are consistent with studies that suggest that the six personality factors identified in captive samples are variants of the essential traits of chimpanzees.