The development of sensitivity to cast and attached shadows in pictures as information for the direction of the source of illumination

The development of the perception of cast and attached shadows as information in pictures for the direction of the light source was studied with children in kindergarten, third and sixth grades, and adults in college. Subjects viewed photographs of objects under four different positions of illumination, with either cast or attached shadows alone, or with both present. Error in angular displacement from the correct position of the light source was 76.5° for kindergarten children, 40.5° for those in the third grade, 34.9° for those in the sixth, and 18.0° for college students. Neither position of light nor type of object affected performance. Results are discussed in the context of a developmental hypothesis of changing interpretation of the relations between pictorial and nonpictorial space from childhood to adolescence.