Extraversion and neuroticism: Investigation of resting electrodermal activity

In the same year that Eysenck (1967) published his biological account of extraversion, Claridge (1967) identified several problems with the theory. In addressing issues raised by Claridge, Robinson (1996) has detailed a promising modification to Eysenck's theory. Drawing on Robinson's theory it was hypothesised that differences in resting electrodermal activity would contrast extraverted-neurotics (low arousal) and introverted-neurotics (high arousal). The 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 SCL and 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.