Psychometric properties of the aggression questionnaire in Dutch violent forensic psychiatric patients and secondary vocational students

The psychometric properties of a Dutch version of Buss and Perry’s Aggression Questionnaire (AQ) were examined in a sample of violent forensic psychiatric inpatients and outpatients and a sample of secondary vocational students. The internal consistency, interitem correlations, and item–scale correlations of the subscales Physical Aggression, Anger, and Hostility were good but turned out to be unsatisfactory for the subscale Verbal Aggression. The four-factor structure of the AQ could not be confirmed, but the four-factor structure of a 12-item version (short form) of the AQ, the AQ-SF, produced an acceptable fit. The test–retest reliability of the AQ and AQ-SF total scores was good, although the test–retest reliability of the AQ-SF subscale Physical Aggression was not satisfactory. The validity of both the AQ and AQ-SF could be demonstrated by meaningful correlations with alternative measures of aggression and personality, but inpatients were not found to display higher scores on the AQ or AQ-SF than the students