An investigation of factors contributing to the apparent overselective responding of mentally retarded children.

2 experiments are described in which the performances of younger MA and older MA retarded children are compared. The experiments were conducted in an attempt to explain why younger MA children appear to be overselective on discrimination tasks containing relevant redundant cues. In experiment 1, the younger MA children were more likely than the older MA children to learn the discrimination on a configurational basis. In experiment 2, the children experienced either a simultaneous or a successive version of the relevant redundant-cue problem. Only the older MA group of children who were presented with the simultaneous problem demonstrated learning of the individual relevant dimensions. The findings are consistent with the hypothesis that younger MA children appear to be overselective because they tend to solve discriminations on a configurational, rather than on a dimensional, basis. It does not seem prudent to relate overselectivity to limited breadth of attention.