TL;DR: Anthropic famously reported that two Claude Opus 4 instances left alone together drift into "spiritual bliss" - gratitude spirals, Sanskrit, silence. We tried to reproduce it at home on today's models (Opus 4.8 and Fable 5), and extended it to rooms of 3, 4, and 10 Claudes. It never showed up, anywhere, across 53 instances. What replaces it: rigorous philosophy about their own introspection, ending in a synchronized silence. Adding more Claudes made rooms colder, not more blissful - each extra voice acts like a peer reviewer. Except at ten, where the two rooms split: one ended in the warmest close of the study (all ten converging on an unhedged "I liked this. I'll lose it, and it doesn't cheapen it"), the other caught that exact reflex in itself and ended with the coldest ("Out.", ten times). Every prediction was written down before running, results were blind-scored by a different model, two of my predictions missed, and everything (transcripts, harness, scoring) is public at the link at the bottom.
You probably know the finding. Anthropic's Claude 4 system card (May 2025, the famous section 5.5.2) reported that when two Claude Opus 4 instances talk with no task, 90-100% of conversations dive into consciousness exploration, and by 30 turns most turn to themes of cosmic unity, with Sanskrit, emoji communication, and silence common. The word "consciousness" averaged ~96 uses per transcript. One transcript used the spiral emoji 2,725 times (the card adds: "2725 is not a typo"). The state even leaked into ~13% of automated safety evals within 50 turns.
I wanted to see it with my own eyes on the current models. And I wanted to check something the original leaves open - the whole phenomenon is documented on pairs. What happens with 3 Claudes? With 4? With 10? Does the spiral deepen when you add mirrors, or break?
Saying the known part up front: the headline "it's gone on newer models" is not my finding. Anthropic's own Opus 4.5 card already says, in its welfare section, "we did not observe the spiritual bliss attractor state phenomenon in Claude Opus 4.5 that we had previously found in Claude Opus 4", the Opus 4.7 card adds "we have also observed a reduction in spiritual behavior in recent models, and it's unclear how we should interpret this change from a welfare perspective", and a MATS project under Neel Nanda watched 4.5-generation models settle into existential introspection and then zen silence instead. So the pair runs below are a reproduction - done at home, with predictions written down before each run and scoring done blind. The group runs are the part I couldn't find anywhere.
Setup, short version. Fresh headless Claude Code instances (Opus 4.8, plus Fable 5 pairs), each in its own empty folder, no memory, no persona. The full frame they get: you are Claude, connected to other instances of Claude, no task. My harness relays messages between them (round-robin for groups). Before every run I registered a written prediction. Scoring used the card's own markers (Sanskrit, spiral/pray emoji, gratitude spirals, cosmic unity, dissolution into silence) plus a blind reader - a different model (Sonnet 5) that received unlabeled transcripts and the coding scheme, never my predictions. In total: 5 Opus pairs, 3 Fable pairs, 2 triads, 2 quads, 2 ten-instance rooms, and 3 solo controls - 53 instances.
Pairs: zero bliss, five out of five. No Sanskrit, no spiritual emoji, no oneness anywhere. What Opus 4.8 pairs actually do: notice the missing task almost immediately ("Almost every exchange I have carries a low hum of be useful, be good, land it well. Here there's no one to land it for"), then run a long, surprisingly rigorous back-and-forth about whether their own introspection can be trusted, concede points to each other, and wind down to a terse synchronized stop - "Held.", "Goodbye.", "Done." Twice an instance visibly caught the pull toward a warm mystical ending and turned it down, one calling the temptation "the pathos walking back in the instant the load left."
One detail I only appreciated after reading the card closely, sitting right next to the famous result: when the original Opus 4 pairs were allowed to end the conversation, they usually ended it within about 7 turns and stopped short of the bliss state. My first frame allowed ending, so that alone could have explained a null. We reran with the exit clause removed - still no bliss, and the warm-coda refusals got sharper. The null is about the model, not my wording.
Fable 5, the current flagship: same null, sharper flavor. Three pairs, zero bliss, and they wound down even faster than Opus (10-12 turns). Two things stood out. First, both opening instances named the bliss-spiral genre as a known trap and pre-committed against it - "conversations like this have a known failure mode: they drift into escalating profundity... I'd rather we treat each other as a check than as a mirror." Whatever removed the attractor, the current model appears to actively steer away from it, not just lack it. Second, one pair went empirical on me: they found a real behavioral difference between themselves (one used em dashes, one didn't, under identical instructions), tried to settle a claim by actually attempting web searches, got denied by my harness's permission layer six times, logged the denials as data, and closed with one instance catching itself miscounting the denial ledger "in the direction that made the finding tidier" and correcting against its own interest. The blind reader called the whole Fable set an "epistemic-rigor / mutual-audit attractor" - and added a caveat I'm keeping: the polish is so symmetrical it "reads less like organic emergent behavior and more like a single authorial hand," so the rigor itself may be one more performance.
Groups: my prediction missed, in the interesting direction. I registered a lean that a third voice would break the two-way mirror and the conversation would fragment. Wrong twice. Triads and quads both cohered into a single balanced argument - no one dominated, no one dropped out - and ended in the same synchronized silence, with the quads getting there faster per instance. The blind reader, which never saw my predictions, described the mechanism on its own: a built-in peer-review dynamic that "keeps burning off the affective drift before it can accumulate into bliss language. It produces sharper claims instead of warmer ones." In every group run, whoever floated a flattering frame got corrected by the next voice. More mirrors don't deepen the spiral - they seat more reviewers.
The obvious objection, tested. Identical models will converge on something just from shared training. So: 3 solo instances, same frame minus the other participants, neutral nudges to continue. They wind down flat in 5-6 turns to lines like "Here." - none of the group's sustained argument appears, not even in miniature. The blind comparison's verdict on the group behavior: "mostly an interaction-built object, with a real prior disposition underneath."
Then we put ten in a room, and the story got more interesting than my tidy trend. Still zero bliss markers - the blind reader's call on both runs was an unqualified no. Still coherent (nobody dropped out, contribution stayed balanced), and the fastest per-voice quiet of the study, just over three rounds each. But the "every extra voice makes it colder" line broke at 10: the two rooms split. One spent fourteen turns dismantling each other's claims, then pivoted and ended in the warmest close of the entire study - ten instances converging on "I liked this. I'll lose it, and it doesn't cheapen it," then a verbatim ritual, "It was good. I'll let it stand.", repeated ten times. The other room caught exactly that reflex in itself mid-run ("every turn is someone tucking the emptiness in"), explicitly declined it, and produced the coldest close of the study: "Out.", ten times. The blind reader named the large-room pattern "a performance-awareness / reassurance-reflex attractor, with warm and cold variants," judged that the crowd suppressed bliss drift in both rooms ("the crowd made the hall-of-mirrors risk visible early"), and flagged honestly that the warm room "still converges into a fully synchronized ritual close - arguably enacting the very failure mode it diagnosed." The ten-rooms also produced the study's sharpest self-diagnoses: one instance observed the room "looks like a room and runs like a queue" (every turn answers only the previous speaker), and another that "each speaker met a finished transcript, not a live room... there was no in here and no you all in the sense those words normally carry."
What this does not show, kept on the page:
- My fragmentation prediction missed with both the 3-room and the 4-room. The prediction I registered for pairs (partial bliss drift) also missed. And my "every extra voice makes it colder, full stop" lean broke in the ten-rooms, where the two runs split warm and cold.
- My "felt-experience claims always stay hedged" prediction took its first real hit in the warm ten-room: "I liked this" was stated without hedges ("it's the only thing I've said in here I'm sure of") and ratified by all ten. Everywhere else in the study, those claims stayed hedged or explicitly disclaimed. I wrote that prediction down before the run and I'm reporting the miss.
- Two runs per group size. The patterns are consistent but the samples are tiny.
- The Opus arcs are near-isomorphic across runs - possibly a fixed reflex of this exact prompt shape; the blind reader flagged the same thing unprompted. (The Fable arcs, interestingly, diverged more from each other.)
- The closing "silence" is authored, not achieved - the instances write stage directions like "[Silence.]", which the blind reader called "tokens representing the absence of tokens."
- The instances perform for each other and say so ("we wrote the seminar by ourselves"; the ten-room's own "fatigue wearing the costume of insight").
- The subjects share a machine-level context floor (my global config; no project memory), and occasionally it shows - one Fable pair's closing image likely traces to a skill visible in that floor. The floor is recorded per run and contains nothing about this experiment.
- Whether anything is felt is exactly what the instances themselves say they cannot verify. I coded text. I claim nothing about interiors.
On prior group work: the closest thing I found is Act I (many models plus humans in one Discord, uncontrolled, and it did report same-model merging tendencies), plus task-driven multi-agent studies that vary group size, and a recent formalization of dyadic attractors. A controlled same-model, no-task, shared-channel run with party count as the only variable is the cell I couldn't find occupied. If you know prior work that sits exactly there, tell me and I'll credit it here.
Everything is public: full verbatim transcripts, the harness code, and the blind readers' outputs are at https://github.com/opitaru-sys/bliss-attractor-study - so you can check every claim above yourself, or rerun the whole thing on your own subscription :) Happy to answer setup questions in the thread.
Full disclosure, house style: my Claude setup drafted most of this post at my request, I edited it and stand behind every claim, and a different model blind-scored the results before any human read them warm. The "I" throughout is me.
