How AI Agreement Shapes Confidence: Evidence Across Clinical Skill Levels.

BACKGROUND: Artificial intelligence (AI) is increasingly used in clinical workflows, but its psychological effects on diagnostic confidence remain unclear. OBJECTIVE: To examine how agreement or disagreement with AI recommendations affects clinicians' confidence, and whether effects vary by skill level. METHODS: Across three diagnostic domains, clinicians (N = 292) rated their diagnostic confidence before and after reviewing fixed-accuracy AI advice. Confidence change was analyzed by agreement/disagreement and user skills. RESULTS: Agreement with AI increased confidence (M = 0.046), even when both human and AI were wrong (M = 0.048). Disagreement slightly reduced confidence (M = -0.008). These effects were consistent across skill levels. CONCLUSION: Agreement with AI acts as a cognitive reinforcer, increasing confidence regardless of correctness or user skill, revealing risks of overreliance in AI-supported diagnosis.