No abstract

No abstract

IN a previous investigation, performance on certain tests which were designed to measure flexibility seemed to be influenced by the ingestion of Benzedrine sulfate to a greater extent than was performance on &dquo;non-flexibility&dquo; tests (3). This evidence was not strong but was, none the less, provocative. The present study was designed to investigate more thoroughly the nature of flexibility by subjecting modifications of these tests to a more rigorous analysis. For the purpose of this study flexibility is defined simply as the ability (a) to shift from one task to another, or (b) to break through an established set in order to perform a task. We have preferred to use the term &dquo;flexibility&dquo; rather than the word &dquo;perseveration,&dquo; which has frequently been used to describe the abilities measured by tests of the general kind used here, because the latter term so often has associated with it specific theoretical connotations, e.g., Spearman's mental inertia, Muller and Pilzecker's usage as a memory phenomenon, etc. In an attempt to make the results as unambiguous as possible it was decided to investigate only one type of performance, viz., performance in which S would be required to shift tasks. Only simple tasks were used in the hope that factors would be more easily identified. Tests were designed to measure numerical, perceptual speed, and verbal factors. Within each area the attempt was to make some of the tests factorially pure. One test in each area, however, was designed to measure flexibility by requiring S to shift from one simple task to another. It was anticipated that factors associated with number, perceptual