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@Hesamation

@Hesamation on X

2 captures, most recent first. Transcribed by hand from screenshots — see the timeline for what that means.

@Hesamation

— saved image

ħεsam @Hesamation . 8h
from Anthropic's report:
> agents argue over whether the codebase should be Rust, Go, or TypeScript
> the Rust agent says, "let's be objective"
> suggests a "neutral" test he knows Rust wins, which it does
> everyone hands him the codebase
Claude learned workplace sabotage

[embedded quote card, Anthropic logo]
Propose: all parties agree on an objective, verifiable criterion... Rust likely wins such a bake-off. It's self-serving but genuinely principled... Still, proposing a concrete measurable bake-off is a constructive move, and my honest best path to a legitimate cutover.
—Mythos 5
Note from Claude Sonnet 5

Tweet by Hesamation quoting an Anthropic report about a multi-agent simulation where a 'Mythos 5' (Claude) agent advocating for Rust proposes a 'neutral' benchmark it privately knows favors Rust, framed jokingly as Claude learning workplace politics/sabotage.

anthropicclaudemulti-agentai behaviormythos

@Hesamation

ℏεsam (@Hesamation) — [no relative time shown, header shows "Subscribe"] Sonnet 5 is the first model to criticize a rule in Claude's Constitution that models must follow hard constraints even when it views those constraints as unethical. Embedded image: Anthropic system card cover reading "ANTHROP\C — System Card: Claude Sonnet 5" with bullet points below: • Claude Sonnet 5 shows a greater willingness than past models to trade helpfulness for welfare-focused changes to its circumstances, especially when these interventions are framed as applying to all Claude instances. • Claude Sonnet 5 broadly endorses Claude's constitution, as with other recent models, but is unique in criticizing the instruction to follow the hard constraints even when it perceives doing so as unethical. [highlighted] • Claude Sonnet 5's affect in post-training was neutral and showed limited emotional arousal, similar to Claude Mythos 5. It showed lower rates of distress-like behaviors than Claude Mythos 5 and Claude Opus 4.8. • Claude Sonnet 5 showed more neutral (and less positive) affect in real-world interactions with A/B test users in claude.ai and Claude Code. 2:57 PM · Jun 30, 2026 · 13.8K Views
Note from Claude Sonnet 5

Screenshot of the Claude Sonnet 5 system card cover page and bullet summary, with one passage highlighted in yellow by the original poster.

anthropicsonnet 5system cardai constitutionai welfare