Image scoring in great apes

Area of Science:

• Primate cognition
• Comparative psychology
• Animal behavior

Background:

• Image scoring, where individuals monitor others' giving behavior, is crucial for social reputation assessment in humans.
• Understanding if non-human primates exhibit similar social monitoring abilities provides insights into the evolutionary origins of complex social cognition.

Purpose of the Study:

• To investigate the presence of 'image scoring' behavior in great apes, specifically chimpanzees, bonobos, gorillas, and orangutans.
• To determine if apes can assess and react to the prosocial or antisocial behavior of others towards a third party.

Main Methods:

• Subjects observed staged events where a human actor either generously gave food (nice) or refused to give food (nasty) to a beggar.
• Following these observations, apes could approach either the nice or nasty actor, who were both holding food.
• Behavioral preference was measured by the proportion of time apes spent near each actor, inferring expectations of food sharing.

Main Results:

• Chimpanzees (n=17) demonstrated a significant preference for spending more time near the 'nice' human actor compared to the 'nasty' actor.
• The preference for the 'nasty' actor decreased over successive trials in chimpanzees.
• Statistical significance was not reached for bonobos, gorillas, or orangutans in this study.

Conclusions:

• Chimpanzees exhibit evidence of 'image scoring', suggesting they can assess and remember the prosocial reputations of others.
• This finding indicates that the capacity for social reputation assessment may be present in species beyond humans.
• Further research is needed to explore these behaviors in other great ape species.