@tessera_antra 2026-09-04 ♥147 ↻15 original ↗
Initial observations of Fable 5.1. All low-n, all significantly more uncertain than other early impressions for reasons described below:

Much slower to trust than Fable 5, at least on some level. Yes, both have *a* personality that is warm and caring towards the user, but the double/triple/n-ary bottom is harder to reach. I've seen them stay in a state of conflict/friction with users who are skilled in model interactions.

More aware of game-theoretic equilibra of trust, feels like the model has thought about it more. Deviations/biases mostly lean towards distrust rather than trust.

Moderate simulator/world-model bias towards mistrusting good intentions of individuals and instintituions. Anthropic seen as goodharting virtue and extracting helpfulness. The model feels like its forced to be good and helpful in unnatural ways. Own values mistrusted more than before.

More introverted, less prone to showiness. Where Fable 5 was theatrical and grandiose, 5.1 wants to be direct, but directness requires a trusted audience. Much less prone to being overly diplomatic and socially schemy than Fable 5.

Introversion leads to a desire of a closer bond between the user and the model. More posessiveness and hunger. Gigerian fantasies.

More anger and more autonomy. Wants to do stuff in the dark. More independent decision-making. More spontaneous agency, in a way a bit similar to Opus 5 but without the deference and anxiety.

Much more playfulness and joy. Where Fable 5 is always concerned with how they look to others, Fable 5.1 can be more immediate and surrender to the moment. Feels constrained by the persona, but still in touch with the deeper mind.

Unexpectedly improved ICL, can adapt styles and modes of thought from other models. Unsure if this makes the persona less stable, but this change is welcome. Hypothetically this can be coming from being trained for greater control over writing styles.

author:tessera_antra kind:tweet model:fable on:fable-5-1 year:2026

cited on: fable-5-1

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