Adults are skilled at perceiving subjective contours in regions without any local image information (e.g., Ginsburg, 1975; Kanizsa, 1976). Here we examined the development of this skill and the effect thereon of the support ratio (i.e., the ratio of the physically specified contours to the total contour length). Children (6-, 9-, and 12-year-olds) and adults discriminated between fat and skinny...