“Hello. My name is Inigo Montoya. You killed my father. Prepare to die.”

Revenge. It lies among the strongest human emotions, and we recognize its appeal. It’s why people watch movies like Rob Reiner’s The Princess Bride and Quentin Tarantino’s Kill Bill. Some instinct drives us to derive momentary, even deep satisfaction from the idea and application of revenge.

But this instinct also causes us to act irrationally, as can be seen in Jared Diamond’s 2008 New Yorker article, “Vengeance is Ours”, in which he profiles the tribal war between the Handa and Ombal clans in the New Guinea Highlands. The war began so long ago many clan members don’t even really know when or why it started in the first place – yet hundreds of men have died. Each death requires a revenge killing organized by the eldest son, each revenge plot results in at least another dozen deaths, and so on in a horrible, needless, self-stoking cycle.

But what if we did not exact revenge? If we allow our tormentor to run free, we deprive ourselves of the personal satisfaction of vengeance and the assurance that he will never hurt us again. But, then again, this satisfaction is just a wretched form of consolation, and probably should not be sought after at all. It seems like a zero-sum game we’re playing. Should we instead leave revenge up to some higher system? The government? The court? God?

Advances over the past few decades in neuroscience could potentially change our understanding of justice and the role revenge plays in it

In America, we leave the majority of the responsibility for exacting revenge up to the criminal justice system. If this seems like a harsh picture of our justice system, think of how you hear people talking about a convicted criminal: they “got what they deserved,” and “justice was served.” We dilute the intensity of personal revenge, and absorb it into the higher order concept of justice.

But there have been advances over the past few decades in neuroscience that could potentially change our understanding of justice and the role revenge plays in it. This idea lies in Joshua Greene and Jonathan Cohen’s 2004 paper, “For the Law, Neuroscience Changes Nothing and Everything”. In their paper, Greene and Cohen break the punitive legal system into two standardizations: consequentialism and retributivism. Both are present in America’s justice system. Consequentialism justifies punishment in its “future beneficial effects,” seeking to minimize crime in the future. Retributivists argue that criminals deserve to be punished for their past actions, an idea essentially rooted in revenge. Greene and Cohen point out that the distinction between the two relies heavily on the idea of free will. Free will is essential to retributivism – how could you argue that a criminal deserves to be punished if his actions are completely out of his control? On the other hand, minimizing potential crime is not reliant on free will. The existence of free will is widely debated, so, without going any further, it’s important to briefly articulate some relevant viewpoints in that debate:

  1. Determinism – a person is just a set of dominoes falling into a preordained shape. Nothing is up to us.
  2. Complete Agency – conscious actions are completely controlled by the person. Our actions are up to us.
  3. Some sort of combination of the two. Particularly common today is the compatibilist argument: free will, in a practical sense, is reconcilable with determinism. That is, every conscious decision we make involves some choice, and our ability to make that choice is proof of free will.

According to Stanford professor Robert Sapolsky, research into the human brain has moved philosophical views further and further away from the complete agency argument, and the majority of scientists concur that compatibilist or even hard determinist views are most scientifically accurate. Today, free will seems to be this ever-receding idea. Our tendencies can be explained and sometimes predicted more and more accurately because of a “personal zeitgeist,” comprising a combination of evolutionary, genetic, psychological, etc. events that we are getting better and better at identifying.

So what does this all mean for our justice system? Rationally, we wouldn’t assign moral blame to a venomous snake for biting a person, nor an epileptic man for hitting someone during a seizure – their actions are out of their control – so could we really blame a murderer if his actions are also likewise out of his control? Does this make retributivism no longer valid? And what should we think of our desire for revenge?

To answer this, I look to Greene and Cohen when they write that neuroscience will change nothing and everything. If we found out one day that everything we do is actually controlled by higher dimensional beings handling literal puppet strings, would that change anything? Would knowing this change what we actually do? Sure, it would be difficult to accept and we’d definitely think about our lives differently – in that sense everything would have changed – but what would we do differently? We would still work, eat, have fun, fall in love; I don’t think people would all of a sudden just give up on life – in that sense nothing would have changed.

So if we do ever get to the point where we know everything is predetermined, our desire for revenge will still be there. We may think about it differently. We may become more sympathetic with criminals and feel pity over relief when we see a man sentenced to life in prison, but I believe it is impossible to override our desire for revenge; it’s such a deep, innate emotion. Maybe progress in neuroscience will result in the decline of retributive justice and a shift to pure consequentialism, but I think it’s more likely that we will hide our retributivist nature in an ostensibly consequentialist and objective justice system. Look at how we treat dogs. We would never admit to assigning moral blame to a stray dog for attacking us, but there is usually some feeling under the sadness and pity while turning it to the pound that it doesn’t just need this to keep itself and others safe; it deserves this. Simply knowing that there is no free will won’t change our behavior. Everything changes, yet nothing changes.

Thus, I don’t think the justice system or human nature will shift in any drastic way in response to neuroscience. What is more likely is that the Handa and Ombal clans will continue their tribal wars, Quentin Tarantino’s movies will continue to gross millions in the box office, and we will still root for Inigo Montoya on his quest to avenge his father’s murder. Because no matter what we may know about free will, justice, or neuroscience, is is hard to uproot the core instinct to strike back at your enemy. Revenge, in the end, is sweet.



Abumrad, J., & Krulwich, R. (Producers). (2017, June 27). Revising the Fault Line [Radio broadcast]. In Radiolab. New York City, New York: WNYC Radio.

BPS (2017, January 10). Revenge is Sweet: The Mood Enhancing Effect of Retaliation. NeuroscienceNews.

Diamond, J. (2008, April 21). Vengeance is Ours. New Yorker.

Greene, J., & Cohen, J. (2004). For The Law, Neuroscience Changes Nothing And Everything. Oxford Handbooks Online.