"I believe in a forgiving God," Newt Gingrich said the other day when he was asked to reconcile his public defense of "traditional marriage" with the fact that he cheated on his first wife with the woman who became his second, then cheated on that wife with the woman who became his third. Americans like forgiveness, whose absence has been compared to taking poison and waiting for the other guy to die. But as Gingrich's example suggests, forgiveness may have its dark side. According to this study published in the December Journal of Family Psychology, in marriages it's the spouses who are pardoned who are more likely to do wrong again.

James McNulty had 135 newlywed straight couples fill out a daily relationship questionnaire for a week. Each spouse recorded anything that their partner had done to upset him or her, and whether the partner had been forgiven. The next day, people who reported that they'd forgiven their partner were nearly twice as likely to report another nasty act as were the people who had held a grudge.

That was one week for newlyweds, which isn't representative of marriage, of course. But McNulty told Stephanie Pappas in January that he also has data on longer marriages, and it points the same way. In couples he followed for four years, he said, it was partners who weren't forgiven who reduced their levels of verbal and physical aggression. In that study, it seems, turning the other cheek resulted in … more bruised cheeks.

No doubt some fire-and-brimstone nations need to know more about the benefits, if not the necessity, of forgiveness. But Americans, who are addicted to this spiritual state, might do well to ponder that forgiveness is no panacea. It can, apparently, be a bit like deciding not to take poison and then watching the other guy eat everything else.