Looking Back: The "Representational mechanism" of Joint Attention in an infant chimpanzee (Pan troglodytes)

An infant chimpanzee's joint visual attention to objects behind him was investigated. A recent study has shown that a 13-month-old infant chimpanzee can follow human social cues including glancing (okamoto, tomonaga, ishii, kawai, tanaka, & matsuzawa, 2002a). In humans, 12-month-olds do not follow gaze to objects behind them but 18-month-olds do (butterworth & jarrett, 1991). In the present study, from 13 months old, the infant chimpanzee had been tested to look at one of two identical objects, which an experimenter indicated by pointing or head turning. The objects were set in front of or behind the subject. In our series of experiments, we used moving or stationary objects as targets. Moreover, the experimenter manipulated a computer at the onset of each block of trials. The results show that by the age of 20 months, the infant reliably followed the experimenter's cues and looked back to the target behind him. Moving targets elicited more responses than stationary targets, and the subject showed more follow responses after having seen the experimenter manipulating the computer.