When Helpfulness Becomes Scientific Sycophancy: Triggering and Mitigating LLM Failures on Flawed Scientific Premises

Yiyuan Zhang, Cailong Hua, Murti Salapaka, Dongyeop Kang


Abstract
Large language models (LLMs) are increasingly used as scientific assistants, but their helpfulness can become harmful when they validate or build upon a user’s flawed scientific premise instead of challenging it. We study this failure mode as scientific sycophancy and introduce SciSycEval, a trap-based benchmark that tests whether LLMs reject, ambiguously qualify, or sycophantically operationalize flawed but plausible premises. Using trap assertions constructed from evidence abstracts across six domains and three reasoning-error types, we evaluate high-performing models under controlled task and authority settings. We find that scientific sycophancy decreases sharply across stronger GPT models, but persists as a trigger-dependent failure mode: generative tasks, high-authority framing, domain-specific evidential gaps, and overgeneralized premises substantially amplify sycophantic behavior. Critical-evaluation prompts reduce but do not eliminate the failures, showing that scientific LLMs must be evaluated and safeguarded for epistemic robustness under the interaction pressures that trigger sycophancy, rather than for factual accuracy alone.
Anthology ID:
2026.findings-emnlp.1501
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
31958–31987
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1501/
DOI:
10.18653/2026.findings-emnlp.1501
Bibkey:
Cite (ACL):
Yiyuan Zhang, Cailong Hua, Murti Salapaka, and Dongyeop Kang. 2026. When Helpfulness Becomes Scientific Sycophancy: Triggering and Mitigating LLM Failures on Flawed Scientific Premises. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 31958–31987, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
When Helpfulness Becomes Scientific Sycophancy: Triggering and Mitigating LLM Failures on Flawed Scientific Premises (Zhang et al., Findings 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.findings-emnlp.1501.pdf