Personality in Free-Ranging Hanuman Langur (Semnopithecus entellus) Males: Subjective Ratings and Recorded Behavior

The authors obtained behavioral observations and personality ratings for 27 free-ranging Hanuman langur males. Subjects were rated using a questionnaire based on the human Five-Factor Model (FFM). Behavioral observations were taken over 5 months using an ethogram that included 50 behaviors. Principal Component Analysis (PCA) of ratings revealed Agreeableness(R), Confidence(R), and Extraversion(R) components. Each personality dimension was associated with a unique set of observed behaviors. PCA of 36 behavioral indices revealed Dominance(B), Involvement(B), and Activity(B) components. Bivariate correlations showed that Agreeableness(R) was negatively correlated with Dominance(B); Confidence(R) was positively correlated with Dominance(B) and Involvement(B) but negatively correlated with Activity(B); and Extraversion(R) was positively correlated with Activity(B). Dominance rank was positively correlated with Confidence(R) and Dominance(B) but negatively correlated with Agreeableness(R) and Activity(B). These results highlight the comparability of behavioral coding and personality ratings and suggest that some aspects of personality structure were present in the common ancestor of Old World monkeys.