“Because the desire for revenge is so closely linked to violence,” McCullough and his co-authors wrote, “it has been fashionable in Western thought since the Stoic and, later, Christian philosophers to view revenge as immoral, irrational, or both.”
More recently, social scientists and psychologists have promoted “the idea that the desire for revenge is indicative of psychological dysfunction. Linking revenge to mental disorder seems reasonable at first glance because the desire for revenge is a common response to extreme violence and trauma.”
McCullough and his co-authors challenged this view, arguing that the more effective and illuminating approach to understanding revenge is to examine its “functional” role, by asking what it does achieve.
Using the language of evolutionary theory, they wrote:
Specifically, we hypothesize that cognitive mechanisms for revenge evolved because their behavioral outputs (i.e., retaliatory impositions of costs or withholdings of benefits) caused individuals to revise downward the net returns they expect to receive by engaging in exploitive behaviors against the vengeful individual in the future, which in turn (a) deters them from efforts to exploit the retaliator or (b) induces them to emit benefits for the sake of the retaliator.
Put another way, revenge and the threat of revenge are a way to get oppressors, exploiters and bullies to retreat.
“The desire for revenge,” McCullough wrote in his 2008 book, “Beyond Revenge: the Evolution of the Forgiveness Instinct,”
isn’t a disease to which certain unfortunate people fall prey. Instead, it’s a universal trait of human nature, crafted by natural selection, that exists today because it was adaptive in the ancestral environment in which the human species evolved.
David Chester, a professor of psychology at Virginia Commonwealth University, replied by email to my inquiry:
Revenge can be a very pleasant experience for many people, at least in the moment. Our research has repeatedly found revenge-related activity in the brain’s dopamine-rich circuits that facilitate feelings of pleasure and reward.
However, Chester went on to say,
this momentary feeling of pleasure quickly fades and in its wake is an increase in negative emotions. This brief pulse of pleasure followed by a “sadistic hangover” mirrors the emotion dynamics we see in addictive behaviors and may serve to reinforce revenge seeking over time as people try to escape their distress by re-experiencing the sweetness of revenge.
What characterizes revenge seekers?
Our research and others’ reliably shows that vengeful people often have a broad constellation of other “antagonistic” traits, such as aggressiveness, spitefulness, psychopathy, sadism, narcissism, Machiavellianism, greed, entitlement, hostility, and callousness.
The common theme among all of these traits is the tendency to pursue one’s own selfish goals at the expense of others. Vengefulness is also linked to being chronically angry. Angrily ruminating on one’s grievances provides the fuel and focus to pursue revenge. Vengeful people are also interesting in that they can be both impulsive and planful.
The result?
When you combine an antagonistic disposition with chronic anger, you get a vengeful personality. Whether those vengeful traits manifest as immediate acts of reactive aggression or more premeditated long-term pursuits of revenge depends on the presence of impulsivity or impulse control.
What are the constraints on excessive revenge seeking and are they in place now?
Formally, a defining feature of most modern societies is that vengeance is removed from the hands of the victim and given over to the state. If someone harms you, you cannot legally harm them back and instead you must appeal to the state to pursue and punish the person who hurt you. This is a remarkably universal legal standard and shows us how important it is to human civilization to curtail individuals’ pursuits of vengeance.
There are also informal sanctions against revenge. Vengeance is morally disavowed by most religions and moral systems (e.g., “an eye for an eye makes the whole world blind”). Further, there’s almost no better way to be excluded from human groups than to be belligerent and aggressive. If you routinely meet slights or injuries with vicious retaliation, you will quickly find yourself socially isolated. These moral and social consequences can be powerful deterrents.
Steven Pinker, a cognitive psychologist at Harvard, argued in an email that “there’s a close relationship between revenge and dominance — bullies and badasses intimidate their targets by a threat of retaliation, not just against actual harms, but against signs of disrespect.”