[Development of the proactive/reactive aggressiveness questionnaire for teachers: factor structure and psychometric properties].

Development of the proactive/reactive questionnaire for teachers: factor structure and psychometric properties. The main purpose of this study was to develop a proactive/reactive aggression questionnaire for children in Spanish, reported by teachers. To develop the questionnaire, we selected eight items from the most widely used questionnaires in English using the criteria of a group of experts. Exploratory factor analysis on a sample of 267 children yielded two dimensions, one of proactive and the other of reactive aggression, consisting of four items each. Both scales showed good reliability and were related to an external criterion such as academic performance.