An Object Classification Test as a Measure of Overinclusive Thinking in Schizophrenic Patients

Abstract

The Object Classification test consists of twelve small objects which can be sorted in ten different ways. It was originally intended as a test of ‘concreteness’, but it was later predicted that patients suffering from overinclusive thought disorder would produce a large number of additional unusual sortings. Results are quoted, both for usual (‘A’) and unusual (‘ Non‐A’) sortings for a standardization group of 120 normals, as well as 34 neurotic patients, 20 endogenous depressives, 35 acute schizophrenics and 37 chronic schizophrenics. It was found that only acute schizophrenics give evidence of overinclusive thinking on this test, and that, of these, only half give an abnormally large number of ‘Non‐A’ responses. Chronic schizophrenics on the other hand are no more overinclusive than normal or non‐schizophrenic subjects, although they give significantly fewer ‘A’ responses than normals. It is possible that overinclusive thinking in a schizophrenic patient is therefore a relatively good prognostic sign, although a confirmatory long term follow‐up study is needed.