arXiv Computation and Language

Language Models Show Conformity Bias in RAG: When the Majority Endorses a Poisoned Claim

Retrieval‑augmented generation (RAG) can expose language models to misleading evidence. In a study of 200 SciFact questions, the Gemma‑3‑12b model’s ability to detect poisoned claims dropped from 25% when a single poisoned document was present to 10% when six mutually agreeing poisoned documents dominated the context. The majority condition caused 34 of 38 questions to shift from detected to undetected, indicating a conformity‑like bias.

arXiv AI
Sep 16

TAME: Token Attribution and Masking for Emergent misalignment

TAME (Token Attribution and Masking for Emergent misalignment) is a three‑stage framework that identifies which training tokens drive harmful behavior in fine‑tuned language models. It first scores tokens by how much fine‑tuning increases their likelihood, then characterizes patterns among high‑attribution tokens, and finally validates them by masking during training. Experiments on Llama and Qwen show that masking the top‑attribution tokens reduces emergent misalignment by 23‑ to 36‑fold, while random masking has no effect.

By Md Rayhanul Masud, Md Rizwan Parvez
arXiv Computation and Language
Sep 18

Towards Safer RAG: Only Agents Capable of System 2 Thinking may Access Untrusted Documents

The paper examines how deliberative (System 2) reasoning affects a Retrieval-Augmented Generation (RAG) model’s vulnerability to knowledge‑poisoning attacks. Using two metrics—Cordon Rate and Leakage Rate—it evaluates six model configurations on 200 SciFact questions. Results show that enabling reasoning lowers both Cordon and Leakage Rates for DeepSeek‑V4‑Flash, indicating reduced behavioral impact from poisoned evidence, though overall attack success increases.

By Mehrdad Ghassabi, Audrina Ebrahimi, Sadra Hakim, Hamidreza Baradaran Kashani
arXiv AI
Oct 5

Misinformation Without Triggers: From Factual Answers to Downstream Decisions

The study investigates how false content in training data can influence language models’ downstream decisions even without explicit triggers. By comparing models trained on misleading versus truthful documents in a controlled decision task and a real‑world bushfire case, the authors find a gap between factual answers and the decisions derived from them: correct facts do not always lead to correct decisions, and removing an injected number does not eliminate the misleading narrative. The research highlights that data poisoning can subtly alter model behavior beyond what is detectable through direct probing.

By Lin Tian, Marian-Andrei Rizoiu
arXiv Computation and Language
1d ago

Can Humans Tell? A Dual-Axis Study of Human Perception of LLM-Generated News

Can Humans Tell? A Dual-Axis Study of Human Perception of LLM-Generated News investigates whether people can distinguish news articles written by humans from those generated by large language models (LLMs). Using JudgeGPT, the study collected 2,318 judgments from 1,054 participants on content from six LLMs, finding that participants could not reliably differentiate machine-generated from human-written text. The research also shows that domain expertise predicts judgment accuracy, distinct response strategies exist, and accuracy declines after about 30 evaluations due to cognitive fatigue.

By Alexander Loth, Martin Kappes, Marc-Oliver Pahl
arXiv Computation and Language
Sep 28

Stale-Document Poisoning: When Outdated Retrieval Overrides Correct Model Answers

The paper introduces "stale‑document poisoning," a temporal alignment failure where outdated retrieval evidence causes retrieval‑augmented generation models to produce incorrect answers even when the model could answer correctly without retrieval. A benchmark of 317 verified knowledge reversals across medicine, law, software, and platform policy shows that outdated evidence flips 30–37% of Llama and Qwen answers, rising to 66–75% when models are explicitly instructed to trust the document. The study demonstrates that providing explicit validity information and a recency‑aware re‑ranker can substantially reduce poisoning, highlighting the need for models to assess whether retrieved evidence remains applicable.

By Md Shamim Ahmed, Lukas Galke Poech, Richard R\"{o}ttger