BackgroundThe State-Trait Anger Expression Inventory (STAXI), a self-report questionnaire, is designed to measure the experience and expression of anger. Reliability and validity of the STAXI have been well established among African and European Americans aged 13 years and older. However, little is known of the use of this instrument among adolescents younger than 13 years and Hispanic American adolescents.ObjectivesObjectives were (a) to test ethnic, sex, and age group differences in STAXI scores in a sample of 11-to-16-year-old African, Hispanic, and European American adolescents; and (b) to assess the psychometric properties of the STAXI among these same adolescents with special emphasis on Hispanic youths, for whom no data are available.MethodsA cross-sectional design was used with stratified quota sampling techniques. Participants (N= 394) were African, Hispanic, and European Americans aged 11–16 years and were drawn from one public middle school and two public high schools in Houston, Texas.ResultsInternal consistency reliability for the anger scales (STAXI) ranged from 0.61 (anger-in) to 0.91 (state-anger) for the younger group (aged 11–13 years), and 0.68 (anger-in) to 0.88 (state-anger) for the older Hispanic Americans (aged 14–16). No notable differences were seen among the three ethnic groups in regards to internal consistency. Results of factor analyses of the five anger scales were similar to those reported originally by the scale author. Ethnicity and age had statistically significant main effects on the anger scales, and there was only one interaction.DiscussionThe use of the STAXI among a tri-ethnic adolescent population is warranted. The anger-in scale may be less reliable, especially among younger adolescents.