Relations were investigated between three measures of individual diffe
rences (Neuroticism, Type A/B personality and Locus of Control) and me
asures of stress in response to the challenge of performing mental ari
thmetic. Three types of dependent measure were recorded, self-report (
stress and arousal), psychophysiological (heart rate and skin resistan
ce) and performance (number of problems attempted and proportion, corr
ect). Relations between the individual difference measures (and their
interactions) and the stress and performance measures were assessed by
multiple regression. Heart rate increased and skin resistance decreas
ed during mental arithmetic, the increase in heart rate being less in
subjects scoring higher on neuroticism. These subjects also reported h
igher stress levels, but no greater increase in stress during the task
. The number of mental arithmetic problems attempted was a complex fun
ction of the combination of the three individual difference measures,
but the probability of a correct answer was related only to Locus of C
ontrol, Internal subjects performing better than Externals. Type B sub
jects increased their probability of a correct answer from the first t
o the second test session, while Type A subjects showed no improvement
. These results show that different types of response to stress are re
lated to individual differences in complex patterns, and several indep
endent and dependent measures are needed to provide a comprehensive pi
cture.