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Biology 202, Spring 2005
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But It Just Feels So Good!
On the neurobiological foundations of having your revenge and liking it too

Katherine Cheng

Epics tales of passion and punishment construct the foundation of our collective human consciousness. Even as children, we are fed stories detailing terrible transgressions and the decisive action inflicted in response to these said offenses, and by the popularity of these examples we are encouraged to feel a degree of righteous satisfaction when the "bad guy" is punished. Contemporary cinema provides ample support for this social norm, as is demonstrated by the following monologue from the opening scenes of director Quentin Tarantino's film, Kill Bill Vol. 1. The speaker, known to the audience only as the Bride, has just awoken from a coma and is intent on exacting punishment on those who wronged her:

Looked dead, didn't I? Well I wasn't, but it wasn't for lack of trying, I can tell you that. Actually Bill's Last bullet put me in a coma. A coma I was to lie in for five years. When I woke up ... I went on what the movie advertisements refer to as a Roaring Rampage of Revenge. I roared and I rampaged and I got bloody satisfaction. In all, I've killed 33 people to get to this point right now. I have only one more. The last one. The one I'm driving to right now. The only one left. And when I arrive at my destination...I'm gonna Kill Bill. 1)Bergen International Film Festival.

Despite the comically horrendous violence utilized to exact revenge upon the offenders, one has to admit feeling a certain degree of satisfaction when she enacts her revenge and is reunited with the daughter torn from her womb. But where does this feeling come from? Why is it okay to commit several murders for the purpose of satisfying ones personal yearning for vengeance? Is this solely an issue of our social and cultural upbringings, or can the answer find its roots across all people, in the very biology of our respective selves?

In respect to these questions, I would like to call to your attention a recent Swiss study concerning "The Neural Basis of Altruistic Punishment" (2004). Authored by scientists Dominique J.-F. de Quervain, Urs Fischbacher, Valerie Treyer, Melanie Schellhammer, Ulrich Schnyder, Alfred Buck, and Ernst Fehr, the study organized men into anonymous pairs of two (A and B) and instructed them to play a laboratory-devised game of money exchange. In one series, Player A was given the option of keeping a sum of 10 Money Units or giving it to Player B, knowing that the money received by Player B in this exchange would in fact be four times the original amount. Player B, in turn, had the option of keeping a total sum of 50 Money Units or returning half (25 MU) to Player A, thus assuring that both players enjoyed equal wealth. If Player B chose to keep the total amount of money, leaving Player A with none, then Player A was given the option of punishing Player B; sometimes, the reprimand was strictly symbolic, while in other situations, experimenters deducted a sum of money from Player B's total. In each case, Player A had one minute to consider whether or not to penalize Player B; during this time, scientists employed a positron emission tomography (PET) to scan Player A's brain for neurological activity. 2)Science Magazine. PET scans of Player As brain during the one minute deliberation period demonstrated increased activity in the dorsal striatum, an area of the brain associated with the processing of rewards and feelings of satisfaction and enjoyment. This activity was only found when a real penalty was inflicted; in situations where the punishment was only symbolic, scientists did not find similar stimulation of the dorsal striatum. 3)Scientific American.

So, what does this all mean? What is the significance of these PET scans? The researchers originally hypothesized that by initiating an exchange with the gift of a sum of money to an anonymous partner, Player A must trust Player B. In return for this trust granted to him by a complete stranger, Player B would, according to social norms governing fairness and interdependence, reward Player A by returning half of his money so that both share equal investments and rewards from the exchange. Thus, in cases in which Player B keeps all of the money, he transgresses these norms governing social behavior, thereby wronging Player A. 2)Science Magazine. As the scans show, when given the opportunity to punish Player B for breaking these commonly accepted standards, Player A experienced psychological redress. That is, in these situations, revenge actually felt good! 3)Scientific American. To this, Dr. de Quervain comments,"These findings reflect the everyday experience that some people are willing to invest much more than others in punishing norm violations." 4)MSNBC Stories from Science.

De Quervain's observation may in fact be better understood when one considers that in all situations, both Players in the exchange remained anonymous and therefore acted as complete strangers. This could account for why Player A felt comfortable and in fact derived pleasure from inflicting "altruistic punishment," or action against a stranger who had broken a social code of behavior. Possibly, he acted not necessarily for himself, but rather out of "altruistic interests" for the good of humanity, collective society, rather than his individual self. Had Player B been a friend or acquaintance, the scans of Player A's brain activity may very well have produced different results. But, that is for another experiment to reveal.

To return to our discussion of Player As brain activity while he deliberated punishing the Player who broke his trust, it should be noted that another area of the brain simultaneously experienced heightened activity. This area, called the prefrontal cortex, generally comes into play when weighing the costs and benefits of a choice. In the case of Player A, his prefrontal cortex became activated while he compared "the satisfaction derived from punishment against the monetary cost of punishing." In fact, the scientists also found that as the cost of punishment increased, the satisfaction garnered decreased. 5)National Geographic. This weighing of options indicates a rational process that is important to remember in this discussion. Upon first glance, it seems quite bestial or "uncivilized" that a human being would feel pleasure from inflicting pain. However, as the scans of the prefrontal cortex indicate, the brain plays host to continual struggles. Though the findings are so new that any conclusive research expanding upon this study have yet to be published, it is possible that if Player A and B were to engage in a similar exchange, but in this instance, removed from anonymity, Player A's prefrontal cortex may indicate increased activity as Player A weighs the pros and cons of inflicting a penalty on a friend or punishing a transgressor of social norms.

In light of these startling findings, what is one left to think? Surely, the results of this study ring true to many if not all, but this is just one report, and there are many questions left unanswered. How/would the results be different if they included women? Given the evolutionarily differing roles of men and women in a community, would the regions of women's brain associated with conflict resolution and group cohesion be activated? Also, this study was conducted using a presumably Swiss population sample. How, if at all, would the results change, if scientists were to apply this experiment to cultures that were more individually-based? In such cultures, social norms would presumably be less important to the identity of the society and the well-being of others. If this is true, would Player As of this sample experience less activity in their dorsal striatum? And finally, to return to the original example of "the Bride," who exacts revenge on over 30-people, there is no possibility of scanning her fictional mind in order to better understand the processes of her behavior. However, she serves as a good, modern day example of an old, familiar archetype—that of the avenging warrior, determined to punish, and in fact, enjoy punishing, those who wronged her.

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