Neural basis of increased costly norm enforcement under adversity

Abstract

Humans are willing to punish norm violations even at a substantial personal cost. Using fMRI and a variant of the ultimatum game and functional magnetic resonance imaging, we investigated how the brain differentially responds to fairness in loss and gain domains. Participants (responders) received offers from anonymous partners indicating a division of an amount of monetary gain or loss. If they accept, both get their shares according to the division; if they reject, both get nothing or lose the entire stake. We used a computational model to derive perceived fairness of offers and participant-specific inequity aversion. Behaviorally, participants were more likely to reject unfair offers in the loss (vs gain) domain. Neurally, the positive correlation between fairness and activation in ventral striatum was reduced, whereas the negative correlations between fairness and activations in dorsolateral prefrontal cortex were enhanced in the loss domain. Moreover, rejection-related dorsal striatum activation was higher in the loss domain. Furthermore, the gain-loss domain modulates costly punishment only when unfair behavior was directed toward the participants and not when it was directed toward others. These findings provide neural and computational accounts of increased costly norm enforcement under adversity and advanced our understanding of the context-dependent nature of fairness preference.

Diffusion of responsibility attenuates altruistic punishment: A functional magnetic resonance imaging effective connectivity study

“…These ROIs were defined as spheres with a radius of 10 mm centered at MNI coordinates of x/y/z 5 230/24/2 mm (left AI), 38/20/0 mm (right AI), 6/46/212 mm (vmPFC), 230/38/30 mm (left dlPFC), 40/ 36/26 mm (right dlPFC) and 24/16/48 mm (dACC). For this small volume of 3,090 voxels (including all ROIs), a cluster size greater than 38 voxels was associated with FWEcorrected P < 0.05 [see also Corradi-Dell'Acqua et al, 2013;Sebastian et al, 2012;Wu et al, 2014]. Note that clusters that survived cluster-level correction for multiple comparisons either over the whole brain or over the small volume were reported.…”

“…The neural and behavioral responses to norm violations do not represent simple heuristics, but are sensitive to social contexts [Güroğlu et al, ; Hu et al, ; Wu et al, ; Yu et al, ], supporting the idea that human motivations to enforce social norms are flexible [Chang and Sanfey, ]. As core regions underlying altruistic punishment, activations of AI and vmPFC predict amounts of punishment to transgressions by respectively signaling norm deviations [Harlé et al, ; Wright et al, ] and valuation of social norms [Gu et al, ; Xiang et al, ] in a context‐dependent manner.…”

Lateral prefrontal/orbitofrontal cortex has different roles in norm compliance in gain and loss domains: a transcranial direct current stimulation study

“…rejection rates in the loss context than in the gain context, suggesting that they were more willing to suffer personal cost to punish norm violators in the loss context. Using functional MRI, Wu et al (2014) further demonstrate that rejecting unfair offers in the loss domain activate the dorsal striatum, an indication of rewarding and satisfactory experience (see also De Quervain et al, 2004;Crockett et al, 2013). It is thus clear from these studies that people have higher demand for fairness in the loss-sharing context.…”

“…Using functional MRI, Wu et al . () further demonstrate that rejecting unfair offers in the loss domain activate the dorsal striatum, an indication of rewarding and satisfactory experience (see also De Quervain et al ., ; Crockett et al ., ). It is thus clear from these studies that people have higher demand for fairness in the loss‐sharing context.…”

“…How to interpret the higher norm compliance in the loss context? One clue may come from the studies that investigate how gain/loss context influences costly punishment (Leliveld et al, 2009;Zhou & Wu, 2011;Guo et al, 2013;Wu et al, 2014). In these studies, the participant carried out an ultimatum game as a responder, considering whether to accept or reject a monetary division proposed by a co-player (the proposer).…”