This study was designed to assess the impact of social support on poststressor cognitive impairment, with the goal of providing a laboratory test of the buffering hypothesis of social support. High or low support was operationahzed as the warm or the neutral behavior of an interviewer, which preceded the experimental stressor, high or low task load Subjects were 32 nonpsychotic female psychiatric inpatients The predicted interaction was found on a poststressor anagram task. The performance of low-task-load subjects was not markedly affected by the interview condition, whereas high-task-load subjects performed significantly better in the warm interview condition. Heart rate data also supported the hypothesized buffering role of support. The buffering hypothesis suggests that social support moderates or buffers the impact of stressful events on mental and physical health. The relationship is most frequently assumed to be interactive, with the buffering value of support maximized during stressful times. The presence or absence of support is thought to have a limited effect during periods of low stress (Cohen & McKay, 1984). For example, Nuckolls, Cassel, and Kaplan (1972) found that neither stressful life events nor psychosocial assets measured early in pregnancy was significantly related to subsequent delivery complications. When both variables were considered conjointly, however, women with high life-change scores and high psychosocial assets had only one third the number of complications of those with high life-change scores and low psychosocial assets. Those with low lifechange scores were not differentiated by psychosocial assets. These data are consistent with a number of other naturalistic studies that suggest that better mental and physical health is associated with higher levels of support (Brown, Bhrolchain, & Hams, 1975; DeAraujo, van Arsdel, Holmes, & Dudley, 1973; Lin, Simeone, Ensel, & Kuo, 1979).