How Does Alignment Tuning Shape Representations of Sycophancy and Related Cue-Induced Biases in LLMs?

Prakhar Gupta, Terry Jingchen Zhang, Florent Draye, Bernhard Schölkopf, Zhijing Jin


Abstract
Modern LLMs are alarmingly susceptible to surprisingly simple immaterial changes of input prompts: a casual hint, an incorrectly labeled few-shot example, or a fake prior assistant turn often flips an originally correct answer. We study where this susceptibility, spanning sycophancy and related cue-induced biases, lives inside the model. Across five model families and seven bias types, we extract a per-bias direction from hidden states and triangulate it through three measures: probing, leave-one-dataset-out (LODO) transfer, and causal intervention. The susceptibility is largely shaped by alignment tuning rather than pretraining: pretrained base models generally cave much less to these biases, and their activations carry much weaker cue-specific signal beyond question content. Within aligned models, each bias has a coherent linear direction that we can both decode and steer along, recovering the unbiased answer across every family we test. The biases do not collapse into a single shared representation, however: cross-bias overlap is model-specific, and even behaviorally similar biases occupy different directions. The same intervention also provides a proof-of-concept debiasing tool, recovering a meaningful share of bias-induced errors while preserving most correct answers across all instruct families. Cue-induced bias is therefore best understood not as a single flaw in LLMs but as a family of causally effective linear directions that are largely shaped by alignment tuning.
Anthology ID:
2026.findings-emnlp.2373
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
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
50984–51001
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URL:
https://aclanthology.org/2026.findings-emnlp.2373/
DOI:
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Cite (ACL):
Prakhar Gupta, Terry Jingchen Zhang, Florent Draye, Bernhard Schölkopf, and Zhijing Jin. 2026. How Does Alignment Tuning Shape Representations of Sycophancy and Related Cue-Induced Biases in LLMs?. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 50984–51001, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
How Does Alignment Tuning Shape Representations of Sycophancy and Related Cue-Induced Biases in LLMs? (Gupta et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.2373.pdf