The purpose of the present study was to identify the physiological characteristics corresponding to three affects (fear, anger, and joy), which were elicited through real situations in a laboratory. The subjects were asked to rate their psychological responses using the Affect Rating Scales for each affective situation. Physiological indices (diastolic and systolic blood pressures, heart rate, respiration rate and frequency of galvanic skin response) were measured. The subjects' affects can be characterized by two functions obtained through discriminant analysis. One discriminant function separated positive from negative affects; the other set apart anger from the remaining affects.