Your research tends to show that as people forgive, their own self-esteem rises. Why do you think this happens?
It seems to me that as people bear the pain that others caused them, there is a tendency for the forgivers to realize that they are stronger than they previously had realized. They see that they can endure pain and in that pain, they can be good to others, particularly to those who acted unfairly and even cruelly. This shows the forgivers that they are good people and this can lead to an increase in liking the self. Too often, when people are beaten down by others, the victims begin to believe the lie that they are less than they truly are. Forgiving helps to correct this lie.