PSYCHOLOGICAL, anthropological, and sociological studies have reported consistent differences between Mexican or Mexican-American and Anglo-American personality structures. Lewis1-3 has published autobiographical studies of members of Mexico City families.4,5 Rorschach patterns have been reported for the Mexicans in Tepozlan by Abel and Calabrisi6 and for Mexican-Americans by Kaplan.7-9 Qualitative psychoanalytic descriptions of Mexican patients have been published by Ramirez,10 Ramirez and Parres,11 and Iturriaga.12 Finally, Diaz-Guerrero13 has constructed a modal portrait of the Mexican personality based on a questionnaire study. If the personality differences described by these investigators do exist, they should be reflected in corresponding differences in psychopathology. Jaco's14 study of differences in incidence rates between Mexican-Americans and Anglo-Americans for hospitalized and nonhospitalized patients in the state of Texas provides some data in support of this hypothesis. The method of