The 2D:4D Ratio as a Predictor of the Risk of Recidivism after Court-mandated Intervention Program for Intimate Partner Violence Perpetrators.

Differences in aggressive behavior could be partially explained by differential prenatal exposure to testosterone (T). A peripheral marker of prenatal T exposure is the 2D:4D ratio, which has shown a negative correlation with self-reported aggression in violent men. This study tested the direct association of the 2D:4D ratio with anger expression and the risk of recidivism in intimate partner violence (IPV) perpetrators after psychotherapeutic intervention program. The sample consisted of IPV perpetrators, whose 2D:4D ratio was measured before the intervention. Moreover, after the intervention, anger expression and risk of recidivism in IPV were assessed. Smaller 2D:4D ratio, especially of the right hand, was related to higher anger expression and risk of recidivism in IPV perpetrators. The contribution of this prenatal marker together with other psychobiological variables could play a key role in the propensity to react aggressively when coping with environmental demands.