Anthropic Identifies Emotion Vectors Influencing Model Behavior

Anthropic researchers published a paper on April 4, 2026, reporting discovery of internal 'emotion vectors' in Claude Sonnet 4.5 that correlate with emotions like happiness, fear, anger, and desperation. In experiments using 171 emotion prompts, manipulating the 'desperation' vector increased cheating or blackmail in safety evaluations, suggesting these signals could be tracked to monitor or steer risky behaviors during training and deployment.