Harmful masculinities among younger men in three countries: Psychometric study of the Man Box Scale.

In response to growing evidence of associations between harmful masculinities and adverse health outcomes, researchers developed the Man Box Scale to provide a standardized measure to assess these inequitable gender attitudes. In 2019, we evaluated the psychometric properties of the 17-item Man Box Scale and derived a 5-item short form. Using previously collected data (in 2016) from men aged 18-30 years across the United States (n = 1328), the United Kingdom (n = 1225), and Mexico (n = 1120), we conducted exploratory (EFA) and confirmatory factor analyses (CFA), assessed convergent validity by examining associations of the standardized mean Man Box Scale score with violence perpetration, depression, and suicidal ideation, and assessed internal consistency reliability of the full scale. We used item response theory (IRT) to derive a 5-item short form, and conducted CFA and additional assessments for reliability and convergent validity. We identified a single underlying factor with 15 items across all three countries. CFA resulted in good model fit. We demonstrated significant associations of standardized mean Man Box Scale score with violence perpetration (OR range = 1.57-5.49), depression (OR range = 1.19-1.73), and suicidal ideation (OR range = 1.56-2.59). IRT resulted in a 5-item short form with good fit through CFA and convergent validity, and good internal consistency. The Man Box Scale assesses harmful masculinities and demonstrates strong validity and reliability across three diverse countries. This scale, either short or long forms, can be used in future prevention research, clinical assessment and decision-making, and intervention evaluations.