llm_society: the composed society at LLM scale (C3) — loop, tests, smoke green

E11 re-instantiated in a population of LoRA agents, closing the paper's stated
gap before submission (GG: a weeks-scale experiment a reviewer would demand).
One grounding knob in the evaluation channel (g*verifier + (1-g)*conformity,
exactly E11); inheritance is identical in all arms and deliberately ungrounded
(children distilled from their source's own answers - self-consumption made
literal). Directed sex = complementary pairing + Dirichlet offspring screened
on the arm's own signal (the verifier never enters the no_grounding loop);
QD selection on verifier-free behavioural distance; terminal-degeneration
fallback copies the parent instead of crashing a sweep. Pure operators
unit-tested (155 green); smoke run end-to-end on the local A4000 already
shows the self-consumption signature (conformity up, diversity down in one
generation). Design, falsifiers, cost table: tasks/workorder-llm-society.md.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BkRLcc18rwT2Lysu6PbG7v

tasks/workorder-llm-society.md

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+# Work order — `llm_society`: the composed society at LLM scale (C3, the paper's stated gap)
+
+**Date opened:** 2026-09-07. **Decision (GG):** run it before PNAS submission — "if it's an
+experiment that can be done in weeks rather than months then any reviewer would ask to see it."
+
+## Question
+
+Does a population of LLM agents under the four composed operators — grounded evaluation, directed
+recombination, diversity-preserving selection, retraining (mutation) — climb and hold capability,
+while each ablation fails distinctly? The LLM instantiation of E11; the paper's largest stated gap
+(Fig. 1's "open" cell).
+
+## Design (mirrors E11; one grounding knob, in the evaluation channel)
+
+Population of `N` agents = LoRA adapters on frozen Qwen2.5-0.5B-Instruct, initialised as light
+per-family specialists (round-robin over families, agent-specific seeds → initial diversity).
+Non-overlapping generations (Wright–Fisher style; no elitism). Per generation:
+
+1. **Produce & score.** Every agent answers (a) a fixed *validation* pool (verifier-scored → true
+   fitness; the selection signal for grounded arms), (b) a fresh per-generation *conformity* pool
+   (prompts only). Consensus = modal normalised answer per prompt; agent conformity = agreement with
+   the consensus. A fixed *test* pool (never selected on) gives the reported fitness.
+2. **Select** `P = N/2` parents by `s = g·fitness + (1−g)·conformity`.
+   Diversity ON: greedy quality-diversity (next parent maximises `s + λ·behavioural distance` to
+   those already chosen; distance = disagreement rate on the conformity pool — verifier-free, so
+   usable in every arm). Diversity OFF: plain top-P by `s`.
+3. **Breed** (sex ON): parents paired by descending behavioural distance (complementary mates);
+   per pair, `n_cand` Dirichlet-weighted merges are screened on the arm's own selection signal
+   (verifier val-pool for grounded arms; conformity for `no_grounding` — the verifier never enters
+   that arm's loop) and the fittest offspring is kept (directed sex, E10). Sex OFF: children are
+   redistilled copies of the selected parents.
+4. **Reproduce** (the inheritance channel, identical in all arms): each child is a *fresh* LoRA
+   trained from the base on (prompt → its source model's own answer) pairs over a fresh training
+   pool — self-consumption made literal; knowledge survives only through the data channel. SFT
+   stochasticity + fresh pools are the mutation operator.
+
+**Arms:** `full` (g>0, sex, diversity) · `no_grounding` (g=0) · `no_sex` · `no_diversity`.
+**Verifier truth is used for reporting in all arms** (test-pool fitness, consensus accuracy) but
+enters the *loop* only where g>0.
+
+## Metrics (per arm × seed × generation)
+
+Per agent: test fitness (overall + per family + worst family), conformity, selection score,
+selected flag, parentage. Population: best/mean true fitness, behavioural diversity (mean pairwise
+disagreement), consensus accuracy, conformity−truth gap. E11's three panels re-drawn at LLM tier.
+
+## Falsifiers (pre-registered)
+
+1. `full` does not exceed `no_grounding` in final best true fitness → grounded evaluation adds
+   nothing at LLM tier; the composed-society claim fails its LLM test.
+2. Ablations do not fail distinctly (no conformity−truth gap in `no_grounding`; `no_sex` matches
+   `full` on assembled capability; `no_diversity` matches on diversity trajectory) → the
+   complementary-contributions claim does not transfer.
+3. Honest alternative outcome: consensus may stay noisy rather than harden into a confident-wrong
+   mean (specialists are wrong *differently* off-family) → `no_grounding` fails by drift, not by
+   conformity; report the observed signature either way.
+
+## Cost & schedule
+
+| Stage | Scale | Compute | Where |
+|---|---|---|---|
+| Smoke | N=4, G=2, tiny pools, `full` only | ~15 min | local 16 GB |
+| Pilot | N=6–8, G=8–10, `full` + `no_grounding`, 1 seed | ~4–10 GPU·h | local overnight / 1 CX3 job |
+| Campaign | 4 arms × 3 seeds, N=8–12, G=10–12 | ~50–150 L40S·h, ~1 day wall-clock as 12 parallel jobs | CX3 (`/imperial-hpc`); rent only if queue fails |
+| 7B confirm (optional) | headline contrast only (`full` vs `no_grounding`, 1–2 seeds) | ~100–300 GPU·h | CX3 / rented |
+
+## Checklist
+
+- [x] Design + falsifiers (this document)
+- [x] `src/llm/society.py` (pure operators + GPU loop), `kind: llm_society`
+- [x] Pure-function tests (consensus, conformity, QD selection, pairing) — 155 green
+- [x] `configs/llm/society_smoke.yaml` → smoke green (exit 0; conformity 0.54→0.75, diversity 0.69→0.41 in one self-consumption generation — the signature is live)
+- [ ] `configs/llm/society.yaml` pilot (full + no_grounding) → sanity-check trajectories
+- [ ] GG gate: review pilot curves before the campaign
+- [ ] `hpc/llm_society.pbs` array job (arm × seed) → campaign
+- [ ] Figure `paper/pnas/make_figs.py` panel(s); fold into main.md (replaces the "open" cell)
+- [ ] 7B headline confirm (optional, post-campaign decision)
+
+## Open design decisions (defaults chosen; GG may override)
+
+- Families: the three *easy* variants at 0.5B (headroom exists; hard variants risk gen-0 inheritance
+  data being mostly wrong → uninformative universal collapse). Revisit after pilot.
+- g for grounded arms: 0.5 (equal weight); sweepable later.
+- Population constant, non-overlapping generations, no elitism (faithful WF; champions must survive
+  through inheritance, not by fiat).
+- Adapter disk hygiene: delete generation t−1 adapters once generation t is trained (keep gen 0 and
+  final); ~35 MB × N × G × arms otherwise.