The relationship of age and extraversion to arousal and performance on a sustained attention task: A cross-sectional investigation using the Mackworth clock-test

H. J. Eysenck has postulated—and received some empirical support for—an inverse relationship between extraversion and arousal level. Age and extraversion have been found to be negatively correlated. These two outcomes led to the conclusion that arousal level must be increasing with age. This conclusion, however, runs counter to evidence which indicates a lowered arousal with old age. In an attempt to resolve this apparent conundrum a sample of 134 men from 32 to 91 years of age participated in the Mackworth Clock-Test of vigilance during which their arousal level was measured by electrodermal activity. One measure of arousal was unrelated to extraversion both within and across young, middle, and old age groups. For the second measure of arousal as age increased a decrease in arousal level was observed and the relationship of extraversion and arousal was found to be a function of age: inverse for young, none for middle-aged, direct for old. In addition no relation was found between vigilance performance and extraversion.