Extraversion and performance: a test of the theory of cortical inhibition.

Hysterics, according to Eysenck, are more extraverted than dysthymics. The primary factor underlying this difference is thought to be differences in cortical inhibition. In the present study, a test was made of the hypothesis that extraversion scores should correlate with scores on performance tasks purported to depend on cortical inhibition. None of the performance measures correlated with extraversion scores. When a subset of subjects with highneuroticism scores were used, only one of the correlations between performance and extraversion reached statistical significance and that was opposite to prediction. In addition, a zone analysis failed to yield significant correlations expected by theory. It is concluded that while extraversion may be important to differential neurotic development, the theory that extraversion, and therefore types of neurosis, is based on cortical inhibition is not supported by the data.