The place of cooperation in the examination of mental disorder

The problem of cooperation is addressed here in relation to the possible invalidation of experimental and psychometric results produced by either a lack of effort or inability, on the part of subjects, to give the necessary attention to make a sampling of psychological function a fair one. The author draws on findings from a group of psychological tests and experiments conducted at the Worcester State Hospital on schizophrenic and other subjects. A rating system for evaluation cooperation level used at Worcester is discussed, as is the complexity of the cooperation problem. Results are considered in terms of: a) the distribution of cooperation an representativeness among the various psychoses and normal subjects examined; b) correlation of cooperation and representativeness with performance; and c) change in score with change in cooperation on selected tasks where the tests were repeated. Correlations of score and cooperation reached modal levels of .60, and changes in score were generally correlated with cooperation.