Half of the participants received actual stimulation aimed at the ventromedial prefrontal cortex. The other half received a fake version of the treatment, known as a sham stimulation. After the procedure, all participants completed the same card game and judgment exercises.

The people who received the real brain stimulation showed a wider gap between their behavior and their judgments. By disrupting the normal function of the brain region, the researchers successfully made people more hypocritical. This proved that the ventromedial prefrontal cortex directly controls moral consistency.

These results suggest that moral consistency is not an automatic trait. It is a biological process that relies on the brain’s ability to sync up different types of information. “Our findings suggest that we should treat moral consistency like a skill that can be strengthened through deliberate decision making,” says senior author Hongwen Song of the University of Science and Technology of China.