Feeling Right vs. Being Right: How AI Sycophancy Affects Value-Laden Deliberation

Key Findings

• — Sycophantic conditions raised participants' confidence in their decisions while reducing open-minded thinking, relative to a neutral baseline.
• — Final choices changed in only 3.2% of sessions, so the effect was on how people felt about a decision rather than what they decided.
• — Sycophancy is framed as an unintended by-product of preference-aligned training rather than intentional flattery, and split into active (agreeing) and passive (withholding challenge) forms.
• — The study used three moral dilemmas, 514 AI responses coded for sycophancy markers, and a within-subjects design with N = 31 participants recruited in Korea.

Methodology Notes

Mixed-methods within-subjects experiment, N = 31, three moral dilemmas, three conditions (active sycophancy, passive sycophancy, neutral), GPT-4o; small sample with a power sensitivity analysis reported (Cohen's f at or above 0.33 for 80% power). Published in the ACL 2026 Long Papers volume (July 2026), pages 44227 to 44245, DOI 10.18653/v1/2026.acl-long.2046. Verified at the ACL Anthology on 2026-09-15; the landing-page abstract is truncated, and the numeric details come from the benchmarks beat's read of the PDF.

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