Forty-one health professional students were videotaped during three consecutive conditions: a 5-min wait for a tardy interviewer, the structured interview for determining the Type A behavior pattern, and a 5-min relaxation period. Afterward, subjects were classified as Type A or B based on audiotapes of the interview. The total amount of activity and the frequency or duration of Type A behaviors were compared between Type A and Type B subjects. In all three experimental conditions, Type A subjects moved their arms more than Type B subjects. During both the waiting and the relaxation periods, Type A subjects sat still less and spent more time exploring than did Type B subjects. During the interview, Type A subjects gestured more frequently than Type B subjects. Nonverbal behaviors correctly identified behavior pattern in 71% of the subjects. The addition of nonverbal behaviors improved the discrimination of behavior pattern above that obtained from verbal behavior alone. The greater activity, restlessness, exploratory behavior, and gestures of Type A persons are consistent with the two major etiologies proposed for the Type A behavior pattern.