Previous research has suggested that the well-publicized loss of abstract ability by schizophrenics may reflect their difficulties with interpersonal communication rather than abstraction deficits per se. To test this hypothesis, the performance of process schizophrenics, reactive schizophrenics, and normals were compared on four Proverbs tests which varied in the amount of interpersonal communication they entailed. Also, to test the hypothesis that the abstraction deficits reflect only difficulties with verbal stimuli, the performance of the three groups was compared on abstraction tests composed of nonverbal stimuli (the Block Design, Object Assembly, and Category tests) and verbal symbols (the Proverbs tests). The results suggest that abstract thinking deficits in schizophrenics are more prominent in tasks composed of verbal stimuli. However, the results did not support the view that either autism or loss of ability to abstract in adult schizophrenics increases peculiarly with the amount of interpersonal interaction built into the task.
New findings for category tests subscales