Extraversion and rapid tapping: reactive inhibition or general cortical activation as determinants of performance differences

Two samples of subjects (n_tot = 22) scoring high or low on EPI-E tapped a morse-key as fast as possible over a 2-min period. As predicted, extraverts showed a lower tapping performance than introverts with differences between groups increasing significantly over time due to greater delays among the extraverts. Within the E dimension tapping differences could be shown to depend significantly only on the subfactor impulsiveness but not on sociability. There were no differences between groups, however, in frequency of involuntary rest pauses. Therefore the effects of extraversion on tapping performance should be explained more in terms of underlying differences in cortical arousal level than in terms of intermittent blocks as part of inhibitory potentials.