Incarcerated thieves, drug dealers and murderers may not be the typical group you imagine doing yoga, but recent studies show that the ancient discipline might be able to play an important role in reducing prison violence. Several studies have shown that yoga helps to improve symptoms of anxiety and depression in prisoners, and now a study at the University of Oxford has found that it also increases focus and, crucially, decreases impulsivity—a known factor in much prison violence.

The Oxford researchers studied 100 prisoners from seven U.K. prisons. About half the prisoners practiced yoga once a week for 10 weeks; the other half were told they were on a waitlist for the yoga class and encouraged to go about their regular exercise routines. Prisoners in the yoga program—two women and 43 men—became less aggressive toward their fellow inmates and felt less stress, as measured by standard questionnaires. The yogis also performed better than the waitlisted group on a computerized test of executive control, suggesting they had become more attentive to their surroundings and more thoughtful about their actions.

“Attention and impulsivity are very important for this population, which has problems dealing with aggressive impulses,” says Oxford psychologist Miguel Farias, one of the study's authors. With less anxiety and aggression, he notes, prisoners should be better able to reintegrate into society when they are released.