The Impact of Threatening Facial Expressions on Negotiation: An Eye-Tracking Study

Facial expressions play a crucial role in social interactions, influencing trust, and decision-making. In negotiations, threatening expressions may convey dominance or hostility, potentially reducing cooperation. This study explores how threatening facial expressions and autistic traits (ATs) affect social decision-making in the Ultimatum Game (UG), focusing on their main effects on UG offers.

Fifty adults participated in the study. A Linear Mixed Model (LMM) was conducted to analyze the main effects of threat level and ATs on UG proposals. In addition, eye-tracking technology was used to investigate participants' visual attention toward different facial areas.

The results revealed a significant main effect of threatening facial expressions, as participants made lower offers in response to high-threat faces. However, ATs did not show a significant main effect on UG proposals. Eye-tracking data showed that participants focused more on the eyes of high-threat faces compared to low-threat faces.

These findings support the Emotion-as-Social-Information (EASI) model, suggesting that emotional expressions, particularly threatening ones, influence negotiation behavior. The study enhances understanding of how facial cues and individual differences in ATs affect cooperation and decision-making in social interactions.