Abstract
Dimensional dominance (either form or color) among retarded and normal children was assessed prior to their being presented with reversal or nonreversal shift task. During the initial learning, the dominant dimension was either relevant or irrelevant to the solution. Both rate of criterion attainment during the initial learning and subsequent shift performance were related to dimensional dominance. If the dominant dimension was relevant, the retarded learned the task as fast as the normal; if the dominant dimension was irrelevant, the retardates learned it with more difficulty than the normals. This result was discussed in relation to the tendency of the retardates' towards being bound to one dimension and no switching to an other.
