The relationships of the process/reactive, paranoid/nonparanoid, length of illness, and length of hospitalization dimensions to schizophrenic abstract thinking deficits.

Attempts to determine whether the quality of schizophrenic thought disorder varies from one type of schizophrenic to another in earlier studies have been hindered by the contamination of the major individual difference dimensions with each other. In the project described here, partial correlations were run between each of two abstraction deficit measures (Proverbs Test Abstract Level and Autism scores) and four independent variables which represent dimensions commonly used as criteria in individual differences research in schizophrenia--Ullmann-Giovannoni Process-Reactive scores, the MMPI Paranoia Scale, length of illness, and length of hospitalization. In each correlation the three noncriterion individual difference measures, the unused abstraction measure, age, education, and WAIS Vocabulary were partialed out. The correlations were also corrected for attenuation. After partialing, level of abstraction was negatively correlated with processness. Autism was positively related to reactiveness and length of hospitalization. Neither of two paranoid/nonparanoid measures used nor length of illness was related to either dependent variable.