Perception of growth from changes in body proportions.

Three experiments examine the perception of age level from computer-generated line drawings of a human body, a Martian, a robot, and a flower that were mathematically transformed using a model of human growth developed by P.B. Medawar. The results suggest that observers' age level judgments are related by a power function to the size of the head relative to the rest of the body but that the exponents of these functions vary systematically across the different body forms. These results are discussed in relation to other research on biological event perception.