Nebylitsyn (1960a，b) showed that reaction time of subjects with strong nervous system
were relatively longer at weak intensities of both auditory and visual stimuli，than reaction time of subjects with weak nervous system，but that when stimulus intensity increased，this differences dissapeared.
A number of studies on individual differences carried out within the Pavlovian model have produced results bearing some similarity to the differences observed between introverts and extraverts.
Zhorov and Yermolayeva-Tomina(1972) found faster reaction times for extraverts and no
ovelap between them and introverts，but the reduction in reaction time as stimulus intensity was increased was greater for the introverts. However，studies of this kind are still too few，and their findings are sometimes contradictory. This study attempts provide some insight into relationship between personality traits and
reaction time. Mean reaction time was found to be longer in extraverts than introverts.
The slope of the curve relating RT to stimuls intensity is steeper in the extraverts than in the introverts. However，significant differences between both groups was not found.