Empathy, a basis for altruistic motivation, is viewed as a developmental process by Hoffman and others. Current measures of empathy, such as the Davis Interpersonal Reactivity Index (IRI), have been analyzed by exploratory factor analytic methods which do not allow for the testing of a developmental model of the simplex form. This study was conducted to test Hoffman's theoretical formulations of empathy. Data from the responses of 679 college students to the four subscales of the Davis IRI (personal distress, empathic concern, perspective taking, and fantasy) were analyzed by multidimensional scaling techniques (ALSCAL). Results indicated that a two-dimensional solution provides the best model. The first dimension supports a simplex model of Hoffman's theory with three of the four Davis subscales; the inclusion of the second dimension in the structure of empathy is questioned. It was found that fantasy clusters separately from the other components and thus may not belong in definitions of empathy. (Author)