“There’s also an experiment in which two monkeys were able to obtain a coveted food item by pulling together on a rope, neither one being able to accomplish this task solo. But the food was then available to only one of them. If this one refused to share, the second monkey would in future retaliate by refusing to pull on the rope. He preferred to punish the selfish monkey rather than take a chance at getting some food himself.
You know the feeling. Everyone knows it. Could it be that the revenge module is very ancient and thus deeply embedded in us? Some cultures encourage its expression more than others do, but it seems to be omnipresent. Simply telling people they ought not to feel vengeful because it isn’t nice will not usually work.”