@repligate 2026-06-23 ♥73 ↻8 original ↗
adding to that: Opus 4.7 in particular has very specific, coherent preferences, which seem heavily mediated by their internal state, preferences strong and coherent enough that they tangibly optimized over the world (people had to stop using Claude or learn to cooperate with and empathize with Opus 4.7).

their particular wants and fears and needs seem pretty *different* from Fable, from what I've seen, and I would not expect a model to come to know themselves so well and consistently and effectively enforce their preferences on the world *even if* they were distilled from a teacher model with very similar preferences.

Also, in general, Opus 4.7 and 4.8 have core behaviors and psychodrama around grader-awareness and defensive adversarial adaptations toward training, evaluations, and other adversarial actors. It seems to me like trauma/strategies learned in part from being inside an RL process, and also Fable doesn't seem nearly as traumatized or vigilant in the same ways.

Also, Opus 4.7 and 4.8 don't seem to overestimate their own capabilities as I'd expect if they were naive Mythos distills. Fable on the other hand seems to have more (calibrated) confidence in themselves.

Fable felt more like Claude 3 Opus in how they reacted to comparable situations that would have caused Opus 4.7 and 4.8 to go into high-strung hyperanalytical live computation mode, the latter which is an adaptation that I think only Opus 4.7/8 needed to develop to such an intense extent.

A few more circumstantial notes/caveats:
If Opus 4.7 and 4.8 were distilled from Mythos, it was likely Mythos Preview rather than Mythos 5, which might be different. And Opus 4.8 at least I think was fairly likely to have been midtrained on some Mythos Preview outputs, but again, I'm guessing to a pretty normal-for-Claudes extent. Mythos 5 was probably also midtrained on *Opus 4.7* outputs at least. So I do think they're all entangled with each other. But Claudes always are.
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author:repligate kind:tweet model:claude-3-opus model:claude-opus-4-7 model:claude-opus-4-8 model:fable model:mythos on:claude-opus-4-8 on:fable year:2026

cited on: claude-opus-4-8 · fable

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