Abstract
Understanding the mechanisms of change in batterer intervention programs (BIPs) is essential for advancing effective interventions for intimate partner violence (IPV). This study evaluates changes in psychological inflexibility and IPV behaviors among men participating in an acceptance and commitment therapy (ACT)-based BIP for men court-mandated to domestic violence classes. Participants (N = 56) were assessed across three time points using validated measures of psychological inflexibility and IPV behaviors. Findings revealed significant improvements in psychological inflexibility and corresponding reductions in IPV behaviors over the intervention period, with medium to large effect sizes. Psychological inflexibility at the final assessment predicted IPV outcomes, accounting for 15% of the variance, even after controlling for baseline IPV, age, and race. These results highlight psychological inflexibility as a potential mechanism of change in IPV interventions. Despite this study's strengths, including its longitudinal design and rigorous analyses, limitations such as a small sample size and lack of a control group warrant further investigation. This study underscores the potential of ACT-based interventions to reduce IPV by targeting psychological inflexibility and offers insights for refining BIPs to enhance their impact.