The relationship between divergent and analytical thinking and hemispheric specialization in man

The two cerebral hemispheres in man are specialized for processing information in diverse ways. One side analyzes input in a logical, sequential manner. The other side is more intuitive, recognizing wholes from parts and combining information to form relationships. Previous experiments have identified individuals within the normal population who have poorly lateralized hemispheric functions. In a college population this generally is manifested by suppression of the synthetic. Gestalt functioning typical of the right hemisphere. The present experiment was an attempt to assess the effect of poor lateral specialization on some higher cognitive abilities, specifically analytical and divergent thinking. Fifty-four Ss from the Arts and Sciences Dean's List and from the Honors Program at University of Houston were screened on the Harris Test for Lateral Dominance and on Nebes' Arc-Circle Test of right hemispheric accessibility. Twenty-four of these Ss were assigned, on the basis of their test performance, to two groups: Well Lateralized Group and Poorly Lateralized Group. The two groups were then compared on two batteries of tests. The Analytic Battery included five tests: Flexibility of Closure, Planning, Concept Mastery, Arithmetic, and Reasoning. The Divergent Battery was composed of eight of Guilford's tests designed to tap flexibility, fluency, and originality of thought. The hypothesis being evaluated was that no differences would be found between the groups on tests in the Analytic Battery because these tap left hemispheric functioning which is not affected by poor laterality in this population. The Well Lateralized Group was expected to be superior on tests in the Divergent Battery, however, because these tests require a bimodal approach for solution. Performance on two tests in the Analytic Battery was significantly higher for the Well Lateralized Group than for the Poorly Lateralized Group. One of the tests. Flexibility of Closure (t=2.68, df=22, p<.02, two-tailed test), probably requires a bimodal approach for solution and, therefore, should have been included in the Divergent Battery. Differences on the second test. Planning (t=2.26, df=22, p<.05, two-tailed test), are more difficult to understand but may be related to the concrete nature of the test items. The only Divergent Test which resulted in significantly different performance by the two groups was Decoration (t=1.81, df=22, p<.05, one-tailed test), which involves spatial elements. The short time limit imposed on the Ss during the Divergent Tests may have prevented group differences on the other tests in the battery. The primary value of the present research has been to elucidate which areas of research in this area might be most fruitful to pursue.