It's the humans, not the data: Geopolitical bias in LLMs originates in post-training, amplified by the language of the prompt

It has generally been assumed that geopolitical bias in language models originates from the training data used during the pre-training phase. We tested seven open-weight LLM pairs consisting of the base model (pre-training only) and the chat model (pre-training and post-training) from seven labs on a paired-scenario forced-choice probe over 28 country pairs in English, French, and Chinese, and found that geopolitical bias originates in post-training rather than in pre-training. Across seven AI l

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ethics.ai (22 May 2026), “It's the humans, not the data: Geopolitical bias in LLMs originates in post-training, amplified by the language of the prompt,” evidence record 3854, https://ethics.ai/record/3854 (originally published by arXiv).

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