By peering inside 25 AI models whose internal workings are publicly available, researchers found a pattern of activity specifically associated with the concept of pain. What’s more, when given the opportunity, some AIs switched off the pattern as a form of “pain relief.” The work, which has not been peer reviewed, has divided AI researchers since it appeared on the preprint server arXiv earlier September, 2026.
The research team identified an AI’s vector associated with pain by comparing how the models responded to user prompts about painful experiences with how they responded to similar sentences about fear, sadness, and other unpleasant states. Then, with the pain vector activated, they fed the LLM mundane prompts and watched how it responded.
The scientists also performed tests designed to determine whether the model was simply reflecting statements of pain made by a human user or was generating a response that described its own “painlike state.” In general, the models did not reflect the user’s pain – the AI’s pain vector fired when the model itself was insulted, for example, but not when the user described their own suffering.