Type A behavior, heart rate and pupillary response: effects of cold pressor and ego threat

The present study tested the hypothesis that Type A individuals would respond to a relevant stressor (ego-threat), but not an irrelevant one (cold pressor), with higher heart rate (HR) and larger pupil size than Type B's. These measures of physiological arousal were taken during baseline and during exposure to each of two sequentially presented, but counterbalanced stress conditions: ego threat and cold pressor. The physiological measures of sympathetic arousal were supplemented with repeated measures of self-reported anxiety. Three distinct findings emerged. First, Type A subjects had higher levels of HR in response to ego threat, but lower levels in response to cold pressor stress, compared to non-stressed baseline levels. Type B's on the other hand had slight, but nondifferential increased HR to the two different stress regimens. Second, the pupillary response to light did not produce results wholly parallel to those obtained with HR, or with the hypothesis that A's are more physiologically responsive than B's. Finally the Type A subjects in all conditions reported less anxiety than did Type B's. The present results generally indicate that A/B differences in cardiovascular arousal do not generalize readily across situations or to all autonomic indices.