Claude Fable won’t answer basic biology questions
TL;DR
Anthropic just released Claude Fable 5, calling it the most powerful AI model it has ever made widely available and praising its skills in biology, among others. But the model won't answer basic biology questions - the kind you'd expect a high schooler to handle. Instead, it hands off the query to the former flagship model, Claude Opus 4.8. It isn't because Fable doesn't know the answers. It's because Anthropic won't let it, by design.
Nauti's Take
This is not a model problem, it is product architecture with the handbrake on. For builders, benchmarks now tell only half the story.
What matters is which capabilities are actually exposed in the real user flow.
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