Sycophancy Is Not One Thing: Causal Separation of Sycophantic Behaviors in LLMs

Daniel Vennemeyer, Phan Anh Duong, Tiffany Zhan, Tianyu Jiang


Abstract
Large language models (LLMs) often exhibit sycophantic behaviors—such as excessive agreement with or flattery of the user—but it is unclear whether these behaviors arise from a single mechanism or multiple distinct processes. We decompose sycophancy into sycophantic agreement and sycophantic praise, contrasting both with genuine agreement. Using difference-in-means directions, activation additions, and subspace geometry across multiple models and datasets, we show that: (1) the three behaviors are encoded along distinct linear directions in latent space; (2) each behavior can be independently amplified or suppressed without affecting the others; and (3) their representational structure is consistent across model families and scales. These results suggest that sycophantic behaviors correspond to distinct, independently steerable representations.
Anthology ID:
2026.emnlp-main.2533
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
57608–57631
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2533/
DOI:
Bibkey:
Cite (ACL):
Daniel Vennemeyer, Phan Anh Duong, Tiffany Zhan, and Tianyu Jiang. 2026. Sycophancy Is Not One Thing: Causal Separation of Sycophantic Behaviors in LLMs. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 57608–57631, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Sycophancy Is Not One Thing: Causal Separation of Sycophantic Behaviors in LLMs (Vennemeyer et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.2533.pdf