“…Investigations of chimpanzee personality have helped to establish the often multi‐dimensional structure of primate social personality traits, a topic which has thus far received less attention in the non‐primate literature (Koski, ). Bonobos also exhibit a highly diverse repertoire of social behavior, however, and although these sister species share many basic behavioral similarities (e.g., Bullinger, Burkart, Melis, & Tomasello, ; Cronin, De Groot, & Stevens, ; Jaeggi, Stevens, & Van Schaik, ; Stanford, ), important differences in their cognition and behavior (e.g., Heilbronner, Rosati, Stevens, Hare, & Hauser, ; Herrmann, Hare, Call, & Tomasello, ; Palagi, ; Wobber, Wrangham, & Hare, ) suggest that bonobos may exhibit a unique social personality structure. Addressing both the conserved and derived features of these species’ personality is crucial for furthering our currently limited understanding of the phylogeny of human personality traits (Weiss, Adams, & Widdig, ) as well as the evolutionary and ecological mechanisms that produce cognitive, affective, and behavioral trait correlations in primate populations (Sih et al, ; Wolf and Weissing, ).…”