Development of the start‐rotation principle in circle production

Abstract

Even in a simple task such as drawing a circle, a graphic production rule governs the syntactical aspects of the movement sequence. The lawful relationship between starting position and rotational direction in circle production has been described as the start‐rotation principle. The principle states that when subjects start drawing a circle at the top, it is most likely that they will use a counterclockwise rotational movement. When subjects start drawing a circle at the bottom, however, they will almost certainly use a clockwise rotational movement. The origin of the principle has been attributed to biomechanical differences between extension and flexion movements, planning activities prior to the initiation of the movements to set the upper limit of circles in space, and cultural factors such as the predominance of the counterclockwise rotational direction in cursive script. The latter, rather global, explanation of the start‐rotation principle has been rejected on the ground that the principle holds for both children and adults, showing that it is not susceptible to development or training. We presently report observations of children's circle productions which do not support the latter argument. Our findings show that, although the start‐rotation principle indeed governs circular movements of young children to some extent, the principle clearly becomes stronger with increasing age. We raise an alternative explanation of the start‐rotation principle which is concerned with end‐point accuracy and the role of visually monitoring trajectory formation. We tested our views in a control experiment with adult subjects.