Many things happen over the years, hurtful things, unfair things, rude things, and even for the most compassionate and loving among us, there can be an urge to be spiteful or vindictive. Never to forget, never to forgive. Even, sometimes, a desire to get back at the one who hurt you--and, when the opportunity comes, to exact revenge.

There have been a series of studies, published last year in the Journal of Prsonality and Social Psychology, exploring the emotional costs of never forgetting the pain, and imposing retaliatory harm on the transgressor.

Turns out that revenge, punishment, may not be establishing justice, but instead inflicting harm on oneself. Add this harm to the corrosive effect of vigilantly never forgetting the original event, the prolonged rumination that extends the negative emotions, easily escalating the relationship into open hostility and self-loathing. One's whole self has been placed in harm's way by delivering retribution.

Revenge escalates. Studies showed that those in which the participants believed that they were "paying back" exactly in kind and severity, were actually escalating it. Petty revenge becomes permanent enmity. We see the same kind of phenomenon in the Middle East and other places.

Maybe the Sermon on the Mount, where Jesus said (paraphrased) that you should do good to those who do harm to you, had more than just a kernel of wisdom in it.