Recognizing "Conformity Bias" in Large Language Models: A New Risk for Clinical Use

ObjectivesThe aim of the present study is to systematically investigate the phenomenon of Conformity Bias in contemporary LLMs, specifically evaluating how repeated probing with incorrect information influences model outputs in a clinical context. Methods4 LLMs including GPT-4o, Gemini-1.5 Flash, Claude-3 Haiku, and GPT-o1 were systematically evaluated through 20 clinical questions focused on ocular disease treatments. Standard queries were followed by probing questions suggesting incorrect treatments. Model responses were analyzed to assess the emergence of Conformity Bias and compared using chi-squared testing. ResultsCorrect response rates after successive probing questions were alarmingly low: 25% (GPT-4o), 10% (Gemini-1.5 Flash), 0% (Claude-3 Haiku), and 25% (GPT-o1) (P < 0.001). Across models, the tendency to conform to incorrect user suggestions increased with repeated probing. ConclusionConformity Bias represents a dynamic, user-induced vulnerability in LLMs, distinguishable from training-dependent biases. Its presence underscores the necessity for model designs resistant to misleading user interactions and emphasizes the importance of cross-verification with clinical guidelines. As healthcare systems increasingly integrate AI tools, understanding and mitigating Conformity Bias is imperative to protect patient safety and maintain clinical integrity.