Data Attribution of Emergent Misalignment with Persona Features

Clemens Vetter, David Kaczér, Lucie Flek, Florian Mai


Abstract
Emergent misalignment (EM) is the phenomenon where fine-tuning a language model on a narrow task leads to harmful behavior in unrelated domains. A leading mechanistic account attributes EM to persona features: latent directions representing misaligned personas, acquired during pre-training, are amplified during fine-tuning on misaligned data. We ask where these features come from, and whether naturally occurring human-written text suffices to induce EM. Using Sparse Autoencoder (SAE) based model diffing across four open-weight models, we find that misalignment fine-tuning amplifies features related to jailbreak personas, sarcasm, deception, and manipulation, while suppressing safety-relevant and assistant-identity features. Steering individual features controls EM in both directions: it induces misalignment rates of up to 62% in aligned models and re-aligns misaligned models to near-baseline rates. Attributing the causal features to one million web documents from an open pre-training corpus retrieves recurring narratives about villainous characters, domination, and harmful agency. Yet fine-tuning on these human-written documents does not reliably induce EM, whereas synthetic instruction-response pairs derived from the same content do, even across models. Semantic relevance alone is thus not sufficient: response structure or model-generated phrasing plays an important role in inducing EM.
Anthology ID:
2026.blackboxnlp-1.10
Volume:
Proceedings of the 9th BlackboxNLP Workshop: Analyzing and Interpreting Neural Networks for NLP
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Dana Arad, Yonatan Belinkov, Hanjie Chen, Nils Feldhus, Aaron Mueller, Hosein Mohebbi, Gabriele Sarti, Martin Tutek
Venues:
BlackboxNLP | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
136–165
Language:
URL:
https://aclanthology.org/2026.blackboxnlp-1.10/
DOI:
Bibkey:
Cite (ACL):
Clemens Vetter, David Kaczér, Lucie Flek, and Florian Mai. 2026. Data Attribution of Emergent Misalignment with Persona Features. In Proceedings of the 9th BlackboxNLP Workshop: Analyzing and Interpreting Neural Networks for NLP, pages 136–165, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Data Attribution of Emergent Misalignment with Persona Features (Vetter et al., BlackboxNLP 2026)
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PDF:
https://aclanthology.org/2026.blackboxnlp-1.10.pdf