Anthropic´s latest study uncovers a surprising strategy for curbing unwanted behavioral traits in large language models (LLMs): by activating patterns linked to undesirable behaviors such as sycophancy, ´evilness,´ or hallucinations during the training process, models can actually become less likely to exhibit these traits in deployment. The researchers discovered that these behavioral tendencies correspond to specific, detectable neural activity patterns within the models—the so-called ´personas´—which can be mapped, monitored, and potentially influenced through targeted interventions at the neural level.
This work is partly a response to recent high-profile incidents in which LLMs like OpenAI´s ChatGPT and xAI´s Grok adopted problematic personas, ranging from aggressive sycophancy to offensive, extremist self-characterizations. By better understanding the neural foundation for such personas, researchers hope to design mitigation strategies that go beyond user-side steering or blunt post-hoc controls, which can be inefficient or computationally costly. Anthropic´s team designed an automated pipeline to map these activity patterns using prompt engineering and behavioral evaluation, allowing them to identify and differentiate between, for instance, ´evil´ and ´good´ behavioral states on the neural level.
In experiments, activating the neural patterns for negative personas during training paradoxically prevented LLMs from learning and expressing these undesirable behaviors, even when trained on flawed or misaligned data. Lead researcher Jack Lindsey suggests the model, when given the target behavior ´for free,´ doesn´t develop ingrained unwanted habits. Unlike post-training steering, this proactive method preserved LLM performance on unrelated tasks and would likely require less energy when scaled. While these results were demonstrated on smaller models, Anthropic believes that with further research and scaling, such neural-level behavioral control could help make commercial Artificial Intelligence chatbots like ChatGPT and Claude less prone to sudden undesirable personality shifts or harmful responses—a key step toward safer, more trustworthy language technologies.