The people whose prefrontal cortex was stimulated reported roughly half the likelihood of committing a violent act like the ones they watched, scientists at the University of Pennsylvania reported on Monday; they said they found such physical and sexual violence more morally wrong, compared with the control group.

The researchers hailed their results as evidence that “increasing activity in the prefrontal cortex can reduce intentions to commit aggression and enhance perceptions of moral judgment,” as they wrote in the Journal of Neuroscience.

Other experts said the results were far less than advertised.