According to a new study published in Biological Psychology, facial attractiveness and positive personality traits independently reduce negative responses to unfair offers in economic decision-making.
In social interactions, both facial attractiveness and perceived personality traits can significantly influence decision-making. Previous research suggests that attractive individuals are often judged more favorably and perceived as more trustworthy and competent. Similarly, individuals with positive personality traits are generally perceived more favorably in social and economic contexts. However, the combined effects of facial attractiveness and personality traits on decision-making, particularly in economic games like the Ultimatum Game (UG), have not been thoroughly examined.
The Ultimatum Game is a standard method used in psychology to study fairness and decision-making, where one player (the proposer) suggests a division of money and the other player (the responder) chooses to accept or reject the offer. Tongjie Li and colleagues examined how facial attractiveness and alleged personality traits of proposers affect the acceptance of fair and unfair offers in the UG. Fair offers involve equal or near-equal splits (e.g., 5/5 or 4/6), while unfair offers are heavily skewed in favor of the proposer (e.g., 2/8 or 1/9).
The study involved 30 female students from Liaoning Normal University in China. Participants were informed that they would receive compensation based on their decisions, with actual payments standardized across participants to ensure consistent motivation. The experiment presented participants with 80 male face images (rated previously for attractiveness) and 80 personality trait words (previously rated for valence).
Each trial began with a fixation cross, followed by a composite image of a face paired with a personality trait word, and then a proposed allocation of money. Participants decided whether to accept or reject the offer, with combinations of high or low facial attractiveness, positive or negative personality traits, and fair or unfair monetary splits.
Electroencephalography (EEG), which measures electrical activity in the brain, was used to capture event-related potentials (ERPs), which are specific brain responses linked to cognitive and emotional processing during decision-making. The researchers focused on key ERPs like the P2, feedback-related negativity (FRN), and P300 components.
Consistent with established norms of fairness in decision-making, the results showed that participants were more likely to accept fair offers than unfair ones. However, acceptance rates were also significantly higher for offers from proposers with high facial attractiveness or positive personality traits, suggesting that these factors biased decision-making in favor of more favorable outcomes, even when offers were objectively unfair.
EEG data revealed that negative personality traits elicited larger P2 components, indicating heightened attentional processing of negative information. High-attractive faces triggered larger late positive components (LPC), reflecting greater cognitive processing associated with the perceived reward value of attractive faces.
Additionally, unfair offers generally produced larger FRN amplitudes, a neural marker of negative emotional response to perceived unfairness. However, this FRN response was attenuated when the proposer was either highly attractive or associated with positive personality traits, suggesting these attributes can mitigate negative reactions to unfair offers. The P300 component, associated with attentional and motivational significance, was larger for fair offers and for proposers with positive personality traits.
Overall, this study demonstrates that facial attractiveness and personality traits independently influence both the behavioral and neural responses to fairness in economic decision-making.
One limitation noted by the authors is the exclusive use of female participants and male face stimuli, which may limit the generalizability of the findings across genders and sexual orientations.
The research, “The impact of facial attractiveness and alleged personality traits on fairness decisions in the ultimatum game: Evidence from ERPs,” was authored by Tongjie Li, Zhiyong Liang, Yan Yuan, Werner Sommer, and Weijun Li.