According to Anthropic (@AnthropicAI), new research identifies 'persona vectors'—specific neural activity patterns in large language models that control traits such as sycophancy, hallucination, or malicious behavior. The paper demonstrates that these persona vectors can be isolated and manipulated, providing a concrete mechanism to understand why language models sometimes adopt unexpected or unsettling personas. This discovery opens practical avenues for AI developers to systematically mitigate undesirable behaviors and improve model safety, representing a breakthrough in explainable AI and model alignment strategies (Source: AnthropicAI on Twitter, August 1, 2025).