Abstract
Background: Collective violence is a significant social issue that impacts individuals' and groups' mental and physical health, social relationships, and educational levels. However, there is currently no valid and reliable scale to measure the acceptance of collective violence among adolescents. Objectives: This study aimed to validate the Multidimensional Scale of Acceptance of Collective Violence (MSACV). Methods: A cross-sectional study design was used to validate the MSACV among teenagers in Tehran in 2022. The sample included 840 teenagers selected through random cluster sampling. Data were collected electronically using MSACV and the Aggression Scale (AS), with the questionnaire link sent to participants' mobile phones. Content validity, concurrent validity, and factor analysis methods were used to assess scale validity. Scale reliability was evaluated through internal consistency, test-retest reliability, and split-half reliability. Results: The content validity ratio (CVR) values ranged from 68% to 91%, and the Content Validity Index (CVI) values ranged from 70% to 94% for the relevant, clarity, and simplicity indices. Exploratory factor analysis (EFA) revealed that the MSACV questionnaire had 7 factors, explaining a total variance of 58.97%. Confirmatory factor analysis (CFA) also supported the 7-factor structure of the MSACV questionnaire. The concurrent validity of MSACV with AS was positive and significant (P < 0.001). Cronbach's alpha coefficient for the overall scale was 0.91, and subscales ranged from 0.70 to 0.94. Test-retest reliability was 0.86, and split-half reliability was 0.74. Conclusions: This study's findings demonstrate that the MSACV is a valid and reliable scale for measuring the acceptance of collective violence among adolescents. This scale can assist researchers and interventionists in the prevention and treatment of collective violence.