5 PRIMATE SPECIES FOLLOW THE VISUAL GAZE OF CONSPECIFICS

Individuals from five primate species were tested experimentally for t heir ability to follow the visual gaze of conspecifics to an outside o bject. Subjects were from captive social groups of chimpanzees, Pan tr oglodytes, sooty mangabeys, Cercocebus atys torquatus, rhesus macaques , Macaca mulatta, stumptail macaques, M. arctoides, and pigtail macaqu es, M. nemestrina. Experimental trials consisted of an experimenter in ducing one individual to look at food being displayed, and then observ ing the reaction of another individual (the subject) that was looking at that individual (not the food). Control trials consisted of an expe rimenter displaying the food in an identical manner when the subject w as alone. Individuals from all species reliably followed the gaze of c onspecifics, looking to the food about 80% of the time in experimental trials, compared with about 20% of the time in control trials. Result s are discussed in terms of both the proximate mechanisms that might b e involved and the adaptive functions that might be served by gaze-fol lowing. (C) 1998 The Association for the Study of Animal Behaviour.