Extraversion and neuroticism: Investigation of resting electrodermal activity

In 1967 Eysenck published his biological account of extraversion and neuroticism. In the same year Claridge identified several problems with this theory. More recently Robinson has detailed a promising modification to Eysenck's theory which addresses many of the issues raised by Claridge. Drawing on Robinson's theory it was hypothesised that differences in resting electrodermal activity (EDA) would contrast extraverted-neurotics (low arousal) and introverted-neurotics (high arousal). The Eysenck Personality Questionnaire (EPQ) was used to identify four extreme groups of female participants: extraverted-stable (n = 16), extraverted-neurotic (n = 15), introverted-stable (n = 8) and introverted-neurotic (n = 16). EDA measures of skin conductance level (SCL) and non-specific skin conductance response (NS-SCR) were collected during two rest periods. Planned contrasts between the extraverted-neurotic and introverted-neurotic groups provided support for Robinson's theory on SCL but not NS-SCR. It was argued that the results for NS-SCR frequency could be accommodated by Robinson's theory if NS-SCR was conceptualised as a measure of cortical reactivity to unspecified stimuli rather than as a measure of tonic arousal.