Social reinforcement in block design performance by brain-damaged, emotionally disturbed, and non-disturbed retardates.

48 retarded adults, equally divided by sex in three diagnostic categories (brain-damaged, nondamaged disturbed, and nondamaged-nondisturbed) were assigned to posttest reinforcement or control conditions on the basis of CA, IQ, and pretest performance on the Block Design. Reinforced subjects were praised for each individual correct block placement on the posttrest; control subjects repeated the test without reinforcement. Both brain-damaged and non-damaged-nondisturbed subjects showed accuracy gains under reinforcement, while nondamaged-disturbed subjects decreased in accuracy. Failure to replicate previous differential reinforcement effects with brain-damaged and nondamaged-nondisturbed subjects, and the discrepant reinforcement effect on nondamaged-disturbed subjects, did not support the use of reinforcement of performance on the Block Design test as an aid in detecting organic damage.