Now that our brains have evolved, we can hold grudges

. [seen on a caveman cartoon]

There's an old saying in Tennessee — I know it's in Texas, probably in Tennessee — that says, fool me once, shame on — shame on you. Fool me — you can't get fooled again. ~ Dubya

Grudge: a feeling of ill will or resentment. From Middle High German grogezen to complain, cry out

Joan cheats on Sam. They have a crisis. They cry. They talk. Sam forgives Joan. Some time later, Joan cheats on Sam again. They have another crisis. They cry. They talk. Sam forgives Joan. Later still, they go through the cycle for a third time. Meanwhile, Sam has not cheated on Joan.

Forgiveness is a prominent concept in contemporary psychology, moral philosophy, and the everyday understanding of a complex social world. There is a growing consensus that forgiveness is good, and that it is better than we naively think it is. Forgiveness is now a central tenet of positive psychology and popular notions of Neo-Buddhist Lebensphilosophie. The interesting thing we have learned from research is that forgiveness is better for the forgiver than for the forgivee. The forgivee is relieved because she is no longer condemned and she no longer needs to be watchful for potential reprisals – assuming that the forgiving is sincere and final. The forgiver may experience even greater relief, however, because he can retire feelings of resentment, memories of the offending event, and plans and plots for revenge. He may even lower his vigilance regarding future betrayals. And herein lies the problem.

Poor Sam might repeat the cycle of betrayal and forgiveness until Joan’s sexual appetite runs dry. With each act of forgiveness, he looks less noble and more like a sucker. Forgiveness loses its meaning if it comes to be seen as a guaranteed link in the chain leading from one betrayal to the next. Evolution has honed our capacity for forgiveness because forgiveness preserves and restores social peace, but it has also honed our capacity for anger, threat, and self-defense. The honing of the latter seems to predate the honing of the former in evolutionary time. Now that humans have both capacities, someone like Sam faces a dilemma. Which response, fierce or forgiving, should be his? A sensitive person like Sam might experience this dilemma consciously, whereas duller minds may automatically engage one response or another. Whether the dilemma is painful also depends on the situation. Presumably, the dilemma will be emotionally intense to the extent that the stakes are high.

It stands to reason that the relative strengths of the motive to forgive and the motive to retaliate vary at different rates with the size of the personal investment and with the number of betrayals already experienced. Suppose Sam and Joan had just started dating when Joan exercises her charms elsewhere. Sam is tempted to forgive because he is in love; yet, he also considers walking out because his investment in the relationship is still small. He can cut his losses and look for love elsewhere. Now suppose Sam and Joan have a mortgage, 3 kids, and 2 dogs. Sam is deeply hurt by Joan’s adventure; he struggles with his wish to forgive her, but he finally does because he has too much to lose if he doesn’t.

Now suppose Sam forgives Joan after her first transgression in both scenarios and suppose Joan does it again. With the passage of time, investments accrue, but so does the incentive to disengage (if not retaliate). Each additional betrayal is not only a renewal of the insult, but it is doubly damaging because it denigrates the earlier act (or acts) of forgiveness. Therefore, the incentive to terminate a relationship (or retaliate) will become stronger. An unqualified focus or demand for forgiveness overlooks that forgiveness loses its psychological power if it is abused (McNulty & Fincham, 2012; see also this earlier post).

Game theory is more sensitive to the subtlety of forgiveness than are the linear models common in positive psychology. Game theory views human interaction through the lens of strategic play. When Sam forgives Joan, he not only regulates his and her emotions, he sends a signal regarding future play. He is saying that he is a cooperator. This signal is ambiguous at first. It might mean that Sam is somebody with whom one can have a mutually rewarding relationship, or it might mean that Sam is exploitable. If all goes well, Sam and Joan live happily, each accepting the sacrifice of not having extra fun. If Joan continues to experiment, Sam will most likely reach a breaking point, at which he terminates the relationship. The challenge for Joan is to know when. With each forgiven transgression, Sam is being moved toward the breaking point; at the same time, each act of forgiveness might mean that the breaking point has just been moved farther into the future. That Joan does not know which of these is true is the glorious ambiguity of interpersonal relations.

Game theorists conduct clever tests of interpersonal strategies. Most of what we know has been learned form computer tournaments among strategies (Axelrod & Hamilton, 1981). A well-known strategy is tit-for-tat (TFT). Simulated Sam and Virtual Joan both start cooperating and know in their heart that they will start defecting once the other defects. As long as both faithfully play TFT, they live a happy if boring life. But stuff can happen. Joan may stumble, be carried away, or run into George Clooney. There could be a transgression that can only be understood as a lapse, an unintended error, an uncharacteristic moment of weakness. Strict TFT players cannot recover from such errors. They are, as game theorists say, GRIM. That’s why TFT was modified to allow a little slop – er – forgiveness. Generous tit-for-tat, tit-for-two-tats, or tat-for-two-tits, whatever it is called, restores mutual cooperation until there are too many defections (usually more than one or two, but this threshold can be moved). Game theorists do not care how people feel. But they have clever ways of modeling and predicting their behavior.

Game theorists do, however, distinguish between forgiving and forgetting. Generous tit-for-tat may forgive, but it does not forget. Once the threshold number of tolerable defections is passed, GTFT defects. In a tournament, a (simulated) player then continues to play (and defect) until whatever predetermined last round is reached. This makes continued defection look like the continuing mutual punishment in a Strindbergian world. Happily, people often have the option to not play. Being able to terminate a social relationship is a benefit in a society that is larger than a small group that hunts and gathers together.

Even if a relationship is terminated, the formerly interacting individuals might continue to live in the same group. This scenario returns us to the original tension between the wish to forgive and the self-protectionist need to remember the other’s penchant for defection. In this scenario, the ability to have a long memory and to hold a grudge is an advantage, however morally incorrect that may sound.

Axelrod, R., & Hamilton, W. D. (1981). The evolution of cooperation. Science, 211, 1390-1396.

McNulty, J. K., & Fincham, F. D. (2012). Beyond positive psychology? Toward a contextual view of psychological processes and well-being. American Psychologist, 25, 101-110.

Most Recent Posts from One Among Many


Decisions between hope and fear

My Return to Theism

A dark version of Abrahamic religion is hard to refute.

Open Questions

How to talk to a professor