Claude Fable 5 won't answer basic biology questions despite being marketed for biology skills
Original: Claude Fable won’t answer basic biology questions
Anthropic's new flagship Claude Fable 5 refuses basic high-school biology questions, redirecting to its predecessor instead.
Anthropic launched Claude Fable 5 as its most powerful model yet, specifically touting its biology capabilities. However, users found the model refuses to answer basic high-school-level biology questions, instead handing queries off to the previous flagship model. The contradiction raises questions about overly aggressive safety filters undermining the model's advertised strengths.
Anthropic released Claude Fable 5 in June 2026, promoting it as the most powerful AI model widely accessible to the public to date. In the official introduction, Anthropic specifically highlighted biology as one of Claude Fable 5's strengths, suggesting significant advances in scientific reasoning and knowledge depth. However, the reality is sharply different from the marketing claims.
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