Relationship of perceived stimulus structure and intelligence: further tests of a separability hypothesis

The representation of objects by moderately and mildly mentally retarded subjects was determined using a classification task in which triads of objects were presented that placed classification by overall similarity relations and classification by shared dimensional relations in conflict. Results indicate that a separability hypothesis of normal perceptual development (Kemler, 1982; Shepp, Burns, & McDonough, 1980; Smith, 1979; Smith & Kemler, 1977) can be extended to retarded populations. Representation as unitary wholistic objects dominated among moderately retarded subjects, and with increasing intelligence, the representation of objects as component separable dimensions began to emerge.