The effect of catch-trials on speed and accuracy among introverts and extraverts in a simple RT task

Three predictions from the model of extraversion put forward by Brebner & Cooper (1974) were tested in a simple RT task. In line with the model, extraverts were found to make more commissive errors and to be more affected by an increase in the catch-trial rate. The third prediction-that extraverts would tend to produce longer runs of decreasing RTs than of increasing RTs in the condition with 10 per cent catch-trials, was not borne out. This effect was, however, seen in the condition with 40 per cent catch-trials although it was not statistically significant, P = 0.06.