Sex-based differences in right dorsolateral prefrontal cortex roles in fairness norm compliance.

Social norms are a common motivator or de-motivator of behavior through the need of humans to comply with acceptable behaviors of their social groups. Converging evidence from functional neuroimaging and noninvasive brain stimulation studies suggest that the right dorsolateral prefrontal cortex (rDLPFC) is involved in social norm compliance. Extending this view, we suggest that rDLPFC may not act uniformly when men and women face different types of fairness norm compliance situations, and that there may be a sequential update of norm compliance after experiencing punishment. Using High-Definition Transcranial Direct Current Stimulation (HD-tDCS) on 100 participants playing a sequence of economic game trials, the current study showed that (1) the right dorsolateral prefrontal cortex (rDLPFC) is involved in both voluntary and sanction-induced fairness norm compliance, (2) it has an opposite role in the two types of compliance, (3) there are sex-based differences in rDLPFC roles in fairness norm compliance, and (4) post-punishment fairness compliance is reduced compared to baseline.