The pleasure of revenge: retaliatory aggression arises from a neural imbalance toward reward

Abstract

Most of daily life hums along peacefully but provocations tip the balance toward aggression. Negative feelings are often invoked to explain why people lash out after an insult. Yet people might retaliate because provocation makes aggression hedonically rewarding. To test this alternative hypothesis, 69 participants underwent functional neuroimaging while they completed a behavioral aggression task that repeatedly manipulated whether aggression was preceded by an instance of provocation or not. After provocation, greater activity in the nucleus accumbens (NAcc) (a brain region reliably associated with reward) during aggressive decisions predicted louder noise blasts administered in retaliation. Greater NAcc activation was also associated with participants' history of real-world violence. Functional connectivity between the NAcc and a regulatory region in the lateral prefrontal cortex related to lower retaliatory aggression. These findings suggest that provocation tips the neural balance towards hedonic reward, which fosters retaliatory aggression. Although such pleasure of inflicting pain may promote retaliatory aggression, self-regulatory processes can keep such aggressive urges at bay. Implications for theory and violence reduction are discussed.

Hormonal underpinnings of status conflict: Testosterone and cortisol are related to decisions and satisfaction in the hawk-dove game

“…This pathway from behavior to cortisol changes is consistent with recent experimental evidence indicating that stable dominant positions buffer cortisol stress responses, whereas stable subordinate positions exacerbate cortisol stress responses (Knight and Mehta, 2017). This pathway is also consistent with evidence that acts of aggressive behavior can be rewarding and may reduce cortisol concentrations (Virgin and Sapolsky, 1997;Chester and DeWall, 2016). Future studies that adopt experimental designs will be important for determining causal pathways linking cortisol changes to hawk-dove decisions.…”

Physical aggressiveness and gray matter deficits in ventromedial prefrontal cortex

“…Finally, the VMPFC plays a critical role in regulating the function of the ventral striatum, a key neural substrate of reward-processing (Haber and Knutson 2009). Ventral striatal activity that is exacerbated and de-coupled from the regulatory functions of the prefrontal cortex has been linked to greater physical aggression (Chester and DeWall, 2016). Therefore, structural deficits in the VMPFC may dysregulate the brain’s reward response to aggression, reinforcing this behavior and serving to promote the physically aggressive phenotype we sought to better understand in this research.…”

Looking for reward in all the wrong places: dopamine receptor gene polymorphisms indirectly affect aggression through sensation-seeking

“…Moreover, these results support the conceptualization of aggression as a rewarding behavior. The role of reward in aggression remains a nascent area of inquiry, but the ability of dopaminergic activity to predict this behavior suggests that, like substance abuse and risky sex, belligerence is reinforced by endogenous reward activity in the brain (e.g., Chester & DeWall, in press). Aggression interventions may benefit greatly from this putative role for positive affect and reward as motivational factors.…”

“…Aggression, oft characterized as stemming from negative affect, may also be motivated by positive affect and hedonic reward (Chester & DeWall, in press). This novel concept suggests that genotypes that modulate the activity of the brain’s dopaminergic reward circuit might also impact sensation-seeking and thus aggressive behavior.…”

“…Indeed, when aggression is in retaliation to a provocation it is reported as pleasant (Ramírez, Bonniot-Cabanac, & Cabanc, 2005). Further, such retaliatory aggression is associated with reward activity in the dopaminergic reward network of the brain: the dorsal (Krämer, Jansma, Tempelmann, & Münte, 2007) and ventral striatum (Chester & DeWall, in press). If aggression is truly a rewarding experience then it should show greater prevalence among individuals high in sensation-seeking, the facet of impulsivity that is the tendency to seek rewarding experiences in the environment (Whiteside & Lynam, 2001).…”