Imagine that you’re an alien visitor to Earth and your primary goal is to learn about human nature. You read human books; you watch human movies, plays, and television; and you visit museums to learn about human history. In your report back to the homeworld, your main finding is likely to be: “Humans really like violence!”
Even among human researchers there is broad consensus that we, as a species, have some fairly profound aggressive tendencies. Yet, whether our hostile proclivities arise because people enjoy the act of aggression is uncertain.
Do People Actually Enjoy Hurting Others?
In the 19th century, Sigmund Freud mused about the possibility that people can derive pleasure from aggressive acts. Freud’s concept of cathartic aggression, in which aggressive acts are thought to function as a therapeutic release of pent up psychic energy, became a medical explanation (and even a treatment) for belligerent people. Modern-day research suggests that Freud’s notion of cathartic aggression remains quite popular and individuals often expect that aggression will leave them feeling better (Bushman, 2002). Yet does aggression actually repair our bad moods?
With my colleague Nathan DeWall (a professor of psychology at the University of Kentucky), I conducted a series of experiments to test whether retaliatory aggression (i.e., revenge) is motivated by and results in an improved mood (Chester & DeWall, 2017). We repeatedly observed that participants only retaliated against someone who excluded them if they expected to feel better because of their aggressive response. We further observed that after they had an opportunity to enact revenge, excluded participants felt the same as their included counterparts. These findings suggest that Freudian expectations that aggression serves a therapeutic end are alive-and-well in motivating aggression and that they may have some factual basis, at least in the short term. Recent, yet unpublished, findings from my lab suggest that the sweetness of revenge fades quickly, leaving individuals feeling worse off than when they started. These findings are just one part of a much larger body of scientific evidence that aggression is often a truly rewarding and pleasant act (Chester, 2017).
Why Would Aggression Feel Good?
Freud’s hydraulic model has been sunk by the modern empirical literature, leaving it uncertain why inflicting pain on someone else might feel good. One clue as to why this is the case came from a brain imaging study I conducted with my colleagues (Chester & DeWall, 2016). In this study, we used functional magnetic resonance imaging (fMRI) to detect that when participants were aggressively retaliating against someone who had repeatedly provoked them, their aggression corresponded to the activity in their brain’s reward circuitry. Further, the more that participants inhibited their brain’s reward response to aggression (via the inhibitory functions of their prefrontal cortex), the less aggressive they were. We interpreted these results to indicate that aggression feels good for the same reasons eating chocolate feels good, it recruits our brain’s reward network.
This biological basis of aggressive pleasure is further supported by studies from behavioral genetics. Approximately 56 percent of the variability we see in aggressive behavior is due to genetic factors (Ferguson, 2010). My colleagues and I conducted two studies that demonstrated how genes that regulate the circulating levels of monoamines (the neurotransmitters that play a large role in feelings of happiness, pleasure, and well-being) are also strongly predictive of whether people have committed acts of real-world aggression (Chester et al., 2016). Such a strong genetic component implies that aggression and its associated feelings of pleasure have a long evolutionary history. Humans, and our evolutionary ancestors that came before us, were often predators and scavengers. Over the millennia, the joy of hunting prey may have bled over into our own species, creating the all too human tendency to feel pleasure from inflicting pain on other people.
Implications for Aggression Reduction
If aggression feels good, can we use this information to reduce the amount of violence we see in the real world? Possibly. As with cigarette smoking, alcohol consumption, and compulsive gambling, if you take away the pleasure, you often reduce the behavior. Interventions and teaching techniques that break the bond between aggression and its corresponding feelings of pleasure are likely to lower violence rates. In extreme cases, such as habitual spouse abusers or violent criminals, it may be appropriate to administer pleasure-blocking medications, such as the opioid antagonist Naltrexone. Though the effectiveness of this approach remains largely untested, there is promise that by taking away the pleasure of aggression, we can make the world a more peaceful place.
If you want to read more about this topic, please check out my recent publication:
Chester, D.S. (2017). The role of positive affect in aggression. Current Directions in Psychological Science, 26(4), 366-370.
David Chester is an assistant professor in the Department of Psychology at Virginia Commonwealth University. His research employs behavioral and brain-imaging techniques to understand the psychological mechanisms that link personal and situational factors to violent outcomes.
Bushman, B.J. (2002). Does venting anger feed or extinguish the flame? Catharsis, rumination, distraction, anger, and aggressive responding. Personality and Social Psychology Bulletin, 28(6), 724-731.
Chester, D.S. & DeWall, C.N. (2016). The pleasure of revenge: Retaliatory aggression arises from a neural imbalance toward reward. Social Cognitive and Affective Neuroscience, 11(7), 1173-1182.
Chester, D.S. & DeWall, C.N. (2017). Combating the sting of rejection with the pleasure of revenge: A new look at how emotion shapes aggression. Journal of Personality and Social Psychology, 112(3), 413-430.
Chester, D.S., DeWall, C.N., Derefinko, K.J., Estus, S., Lynam, D.R., Peters, J.R., & Jiang, Y. (2016). Looking for reward in all the wrong places: Dopamine receptor polymorphisms correlate with aggression through increased sensation-seeking. Social Neuroscience, 11(5), 487-494.
Ferguson, C.J. (2010). Genetic contributions to antisocial personality and behavior: A meta-analytic review from an evolutionary perspective. The Journal of Social Psychology, 150(2), 160-180.