The origin of representational drawing: a comparison of human children and chimpanzees.

To examine the evolutional origin of representational drawing, two experiments directly compared the drawing behavior of human children and chimpanzees. The first experiment observed free drawing after model presentation, using imitation task. From longitudinal observation of humans (N = 32, 11-31 months), the developmental process of drawing until the emergence of shape imitation was clarified. Adult chimpanzees showed the ability to trace a model, which was difficult for humans who had just started imitation. The second experiment, free drawing on incomplete facial stimuli, revealed the remarkable difference between two species. Humans (N = 57, 6-38 months) tend to complete the missing parts even with immature motor control, whereas chimpanzees never completed the missing parts and instead marked the existing parts or traced the outlines. Cognitive characteristics may affect the emergence of representational drawings.