Exploring and reexploring issues of integrality, perceptual sensitivity, and dimensional salience.

Some observations that can be described conveniently by investigators in terms of dimensional sensitivity and dimensional salience actually need not implicate the psychological reality of the dimensions for the subjects. The developmental hypothesis that stimuli are perceived often as integral in early childhood can account for such phenomena only with the assumption that young children often apprehend objects as global wholes, related to one another by overall similarity. Classification data, recently presented by J. R. Aschkenasy and R. D. Odom (Journal of Experimental Child Psychology, 1982, 34, 435-448) can be reinterpreted in this way. On this reinterpretation, Aschkenasy and Odom's findings are exactly what the developmental form of the integrality-separability hypothesis predicts. Moreover, a variety of other findings and lines of inference converge on the conclusion that, in young children, the use of overall similarity relations to organize perception and cognition predominates over the use of dimensional relations (and that the relative balance between these stimulus relations changes in development). Examples are selected from the literature on the natural development of word meanings, as well as from the literatures on children's and adults' classification.