Fairness, Not Emotion, Drives Socioeconomic Decision-Making

Emotion and fairness play a key role in mediating socioeconomic decisions in humans; however, the underlying neurocognitive mechanism remains largely unknown. This exploratory study unraveled the interplay between agents' emotions and the fairness of their monetary proposal in rational decision-making, backed by ERP analyzes of N170, Late Positive Potential (LPP), Feedback Related Negativity (FRN) and P3a at a group as well as a strategic level. In a time- bound ultimatum-game paradigm, 40 participants were exposed to three distinct proposers' emotions (Happy, Neutral, Disgusted) followed by one of the three offer ranges (Low, Intermediate, High). Our findings show a robust influence of economic fairness on acceptance rates. A multilevel generalized linear model showed offer as the dominant predictor of trial-specific responses. Subsequent clustering grouped participants into five clusters, which the Drift Diffusion Model corroborates. Pertinent neural markers demonstrated the recognition of facial expressions; however, they had minimal effect during socioeconomic decision-making. Our study explores individualistic decision-making processes revealing different cognitive strategies.