Anthropic reduces Fable 5 biology safeguards false positives

Fable 5's biology safeguards have been updated to substantially reduce false positives, decreasing biology-related model fallbacks by about 85%. This change allows Fable 5 to handle a wider range of biology tasks, including everyday health and educational questions and clinical tasks for healthcare professionals.

The safety classifiers for Fable 5's biology safeguards were refined through a rewritten constitution, updated training data, and retraining. This process aimed to ensure the classifier accurately triggers for harmful or dual-use research content while enabling a wider range of benign and beneficial uses.

Fable 5 still falls back to Opus 5 for requests related to virology, toxicology, and molecular design due to potential dual-use risks, preventing its use for professional biology research and drug development at this time.

The initial broad biology safeguards were implemented to mitigate risks associated with Fable 5's advanced capabilities, balancing the potential for misuse with the desire for rapid access to beneficial applications in biology and medicine.

Anthropic acknowledges that some false positives will persist and remains committed to developing safe, scalable pathways for researchers to utilize their most capable models via trusted access.