A study compared normative communication apprehension (CA) data on Mexican American high school and college students with CA data from other Hispanics speaking English in order to determine the extent to which the subjects' self-perceived competence in a language was related to CA in that language. Subjects were 388 Mexican American and 41 Anglo students enrolled at Pan American University (Texas), and 252 Mexican American and 31 Anglo high school juniors and seniors from a large Texas public high school. Subjects completed two versions of the Personal Report of Communication Apprehension (PRCA-24)--the first dealing with apprehension associated with speaking English, the second associated with speaking Spanish. Results indicated that (1) CA in the dominant language was lower than in the second language across communication contexts, (2) CA levels increased as the measures moved from more informal, personal contexts to the more formal, less personal contexts; (3) women experienced more CA than men across situations on both languages; (4) subjects had higher CA levels than those of other previously tested Hispanic groups; (5) CA patterns were consistent with those of previously tested bilingual samples; (6) a significant relationship exists between CA and language proficiency in both English and Spanish; and (7) CA levels for the Mexican American students were higher than those of Anglo students. (Tables of data and 72 references are included.) (Author/HTH)