We don’t usually think of anger and resentment the way we think about drugs or alcohol. But growing evidence suggests that, for many people, the craving for revenge follows the same patterns as substance abuse and addiction, triggering powerful biological urges that can spiral out of control and destroy lives. Recent neuroscience discoveries show that your brain on revenge looks like your brain on drugs. Real or imagined grievances (perceived mistreatment, humiliation, shame, victimization) activate the anterior insula — part of the brain’s “pain network.” In response, your brain activates its reward circuitry, causing dopamine to flood your brain, producing...