Stimulus overselectivity is widely accepted as a stimulus control abnormality in autism spectrum disorders and subsets of other populations. Previous research has demonstrated a link between both chronological and mental age and overselectivity in typical development. However, the age at which children are developmentally ready to respond to…

Children, ages 9 to 13 years, made judgments of proportion with a variety of graphical elements in 2 experiments. A characteristic pattern of over- and underestimation was observed; this pattern was also present, but previously unnoticed, in judgments made by adults. (MDM)