Emotional intelligence has been defined as "the ability to monitor one's own and others' feelings and emotions, to discriminate among them, and to use this information to guide one's thinking and actions" (P. Salovey and J. Mayer, 1990). As a subset of social intelligence and of personal intelligences (H. Gardner, 1983), emotional intelligence involves a mental aptitude that assists in the cognitive processing of affect (J. Mayer and P. Salovey, 1993). Three studies are used to illustrate the concept of emotional intelligence and how it has been measured so far. These are: (1) a study of the ability to recognize the emotional content of visual stimuli conducted by J. Mayer, M. DiPaolo, and P. Salovey (1990) with 139 undergraduates; (2) a study of a measure of individual differences in the ability to attend to, clarify, and manage emotions by P. Salovey and others (1995) involving 86 subjects; and (3) a study of the accurate identification of emotion by J. Mayer and G. Geher (1996) with 40 participants. Implications for the impact of emotional intelligence on achievement, emotional well-being, and culture are discussed. (Contains 41 references.) (SLD)