From Sign to Action: Studies in Chimpanzee Pictorial Competence
Alenka Hribar (Max Planck Institute for Evolutionary Anthropology, Leipzig) and Göran Sonesson (Centre for Cognitive Semiotics [CCS], University of Lund)
The present study investigated the abilities of the nursery-reared six-year-old chimpanzee (Pan troglodytes) Alex to interpret different iconic signs, such as video clips, colour photographs, black-and-white photographs, and line drawings. The method we used to investigate this was the “Do as I do” procedure: the experimenter first demonstrated an action and then asked Alex to repeat the action by saying “do this”. Alex was first trained to copy 24 actions and was then tested on 46 novel actions. After this initial training phase we conducted 4 experiments where Alex was asked to copy a known action, after this action was demonstrated to him either live, as a video, a coloured or black-and-white photograph or a black-and-white line drawing. In addition, coloured photographs could show an action in its final or in the penultimate stage. The criterion for judging the capacity of the chimpanzee to extract information from the signs was the extent to which Alex executed the actions for which the signs stood. Throughout the experiments, Alex has shown himself to be capable of executing different action, being prompted by live demonstrations, videos, black-and-white and colour photographs (but not line drawings), no matter if the latter showed the penultimate or the final stage of the action. Therefore, the results suggest that video and picture understanding is within the purview of chimpanzee capacities.