Abstract # 121:

Scheduled for Monday, September 19, 2011 09:15 AM-09:30 AM: Session 17 (Meeting Room 408) Oral Presentation


A. F. Hamel and M. A. Novak
Univeristy of Massachusetts, Amherst, Department of Psychology, Tobin Hall, 135 Hicks Way, Amherst, MA 01002, USA
     Eavesdropping is an efficient strategy in that it allows an individual to observe and acquire important information about conspecifics (i.e. dominance rank), exhibited during social interactions. The observer is afforded the benefit of information without the costs of potentially aggressive contact. Previously, we have demonstrated that rhesus monkeys eavesdrop on dominant and submissive facial cues presented by human experimenters during social interactions. However, these same subjects performed poorly on a task that required them to eavesdrop on interactions presenting information about experimenters’ possession of a food item. The aim of the present study was to modify these food-sharing interactions to overcome certain perceived limitations and to simplify the information presented. Three male and six female rhesus monkeys, ranging in age from 4 to 24 (mean: 10.4 years), were presented with two social interactions which displayed the sharing of either a desirable treat or a piece of monkey chow between human experimenters. When allowed to request a treat from either a “treat giver” or a “chow giver”, subjects preferred to request a treat from an experimenter that they had observed sharing a desirable treat (binomial probabilities: p<0.05). Treat and chow giver roles were randomized across 20 trials. Performance on the food-sharing task was enhanced by the modifications, providing evidence that rhesus monkeys are able to eavesdrop on non-facial information presented during social interactions.