A short critique of the psychophysiology of individual differences

Eysenck's arousal theory of introversion€xtraversion: A converging measures investigation.

“…This result was successfully demonstrated; that is, despite double-blind administration of the caffeine and placebo conditions, both the low and high levels of caffeine administration led to significant decreases in deactivation–sleep (sleepiness), but only the highest dosase level led to an increase in high activation (jitteryness). The second purpose in using the ADACL was to respond to the call by Gale and Edwards (1983) for IE research that would examine possible interactive effects of personality differences with arousal manipulations using a subjectively described level of activation-arousal. Although resting levels of arousal may be described as equivalent by introverts and extraverts on such a subjectively anchored scale (as they were in this study), changes in their phenomenological experience of arousal would not necessarily be the same under equal conditions of manipulated arousal (e.g., with caffeine administration).…”

“…In a critical review of psychophysiological research on the IE dimension, Gale and Edwards (1983) made an appeal for more process-related investigations that focused on the interactive nature of cognitive, behavioral, and physiological aspects of individual differences. In addition, Gale (1981) contended that psychophysiological research on the IE dimension has typically been too reductionistic in its approach, emphasizing the physiological domain at the expense of the behavioral and experiential domains.…”