Research on forgiveness suggests that people who are able to forgive others live longer, happier lives than people who hold onto resentments. People who practice forgiveness are more likely to have healthier relationships, fewer symptoms of depression and anxiety, stronger immune systems and better overall health.
People who don't practice forgiveness are more likely to bring anger and resentment into relationships, be unable to enjoy the present, experience anxiety or depression, and have more health problems.
One study by Hope College psychologist Charlotte vanOyen Witvliet asked participants to think about a person who had hurt them, and the researchers monitored the participants' blood pressure, heart rates and facial tension. They noticed that when the study subjects recalled grudges, their blood pressure and heart rates increased and they perspired more. The subjects were then asked to imagine forgiving their offender, and they showed fewer signs of stress.
Another study by Everett L. Worthington, Jr. measured the levels of cortisol in the saliva of 39 people in relationships. Those in poor or failed relationships who scored lower on a test to assess willingness to forgive showed higher levels of cortisol, while those in good relationships who scored higher on the forgiveness test showed normal cortisol levels.
Typically, psychologists recommend their clients practice forgiveness but caution against false forgiveness. Inversely, some psychologists believe that victims of sexual abuse are empowered by not forgiving their abusers.