Behavioural and physiological aspects of the augmenting-reducing dimension

Reducing-augmenting, sensation-seeking and extraversion-introversion are discussed in the context of strength-of-the-nervous-system theory and two experiments are reported. Experiment 1 showed that high scorers on Vando's Reducer-Augmenter Scale (RAS) (stimulus-intensity reducers) may be identified with sensation-seeking, as measured by Zuckerman's Sensation-seeking Scale, and extraversion, as measured by the Eysenck Personality Inventory. Augmenters' electrodermal responses habituate more slowly than do those of reducers to a relatively strong stimulus. Reducers prefer loud music and apparently need fewer hours of sleep. Female reducers consume relatively more stimulant drinks than female augmenters. Reducers have significantly higher resting systolic blood pressure than augmenters, a finding that was confirmed in the second experiment. However, Experiment 2 failed to find the expected relationship between augmenting-reducing as determined by the RAS and performance on the Kinaesthetic Figural Aftereffects Test.