The Type A behavior pattern is defined as an action-emotion complex that can be observed in any person who is aggressively involved in a chronic, incessant struggle to achieve more and more in less and less time, and if required to do so, against the opposing efforts of other things or persons. The dimensions of this coronary-prone behavior were further explicated by examining how Type A and Type B college students differentially responded to and interpreted social cues of approval. Subjects (N=126), classified as either Type A or Type B, were assigned to two conditions, i.e., high task importance or moderate task importance, and viewed a videotape of vignettes labeled clearly approval, no approval, or ambiguous remarks, of a professor commenting to a student about a paper. Results indicated that substantial differences existed in how Type A and Type B individuals perceived approval-rated vignettes, but no apparent differences in how they perceived no approval-rated vignettes. Data suggest that A's, in the high importance condition, and to a lesser extent in the moderate importance condition, respond to the approval-rated vignettes with significantly less certainty that approval has been given, than the B's. (PAS)