Emotions Drive LLM Negotiation Outcomes: Angry Buyers Fail, Happy Buyers Succeed

A recent study published on arXiv (2608.06922) explores the impact of prompt-conditioned emotions on price negotiations involving LLMs. Researchers assigned one of six emotional states to buyer and seller agents, who then negotiated over 350 actual consumer products under two budget scenarios. The findings revealed that emotions significantly influence negotiation outcomes: angry buyers rarely reach agreements (0.39% deal rate), while happy buyers achieve agreements more frequently (28.91%) but secure less favorable prices compared to fearful buyers. The influence of emotions varies by role: buyer emotions primarily affect acceptance and rejection, while seller emotions influence concession behavior. These emotional dynamics affect not only the language used but also the final terms of the deals, underscoring the significance of emotional modeling in AI negotiation systems.