Giorgio Gilestro
84124de143
Clarity pass over the main text (36-item audit), Discussion rewrite and cut, acknowledgements, Souly et al. as ref 62, lettered SI panels, model section moved under Results; plus the untracked curriculum/society/compose/smol configs, runners, figures, stats and tests that the SI already cites. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com> Claude-Session: https://claude.ai/code/session_01Y64o8FKP7rCuXzC48pxpMm
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llm_curriculum_v5_cull — differential reproduction in the six-generation population
Claim tested (manuscript revision 2026-09-12). In the six-generation population recombination
bought speed but not level: the declinable-merge arm led early and finished level with never merging.
The population had no differential reproduction (lineages were never culled), and the Discussion
predicted that with it a merged lineage's early lead would be inherited by more descendants and turn
into a level advantage. This run adds truncation selection: after every generation's measurement the
lowest-scoring lineage (all-families accuracy) is re-founded from the highest-scoring one, keeping
its own curriculum slot (cull: true; cull_step/inherit_slot in src/llm/curriculum.py;
ties leave the population alone). Arms: isolated + culling and declinable society + culling,
read against the existing isolated and veto arms. Latin square, Qwen2.5-1.5B, 3 training seeds
(hpc/llm_cull.pbs, ~35 min per seed on one L40S). Figure curriculum_cull.png; numbers from
figures/stats_llm_curriculum.py and the per-generation tables printed in the revision log.
Result — parity again; the prediction is not supported
- Final best-lineage accuracy (all six families), mean of 3 seeds: never merge 0.796; declinable merge 0.792; never merge + culling 0.804; declinable merge + culling 0.793.
- Contrasts (per seed; mean ± 95% CI): culled declinable − culled never-merge −0.011, −0.014, −0.008 (−0.011 ± 0.003, below in 3/3); culled declinable − declinable +0.001 ± 0.007; culled never-merge − never-merge +0.007 ± 0.030 (−0.022, +0.028, +0.017).
- The early lead survives, the level does not. Best lineage at generation 1: declinable 0.680 and culled declinable 0.679 against never-merge 0.601 and culled never-merge 0.638; by generation 5 all four sit at 0.78–0.80. Population mean: culling lifts the mean early (generation 1: 0.577 vs 0.477 for the never-merge arms) because the best genome is copied into the worst slot, but the final means converge too (0.775–0.786).
- Selection was active throughout: exactly one cull per generation in every arm and seed (no ties); the culled slot rotated among all three lineages. Declines in the culled declinable arm rose with generation as before (0.33 → 1.00).
- Retention of taught families at generation 6: 0.78–0.79 in all four arms.
Reading. Under a curriculum that delivers every skill to every lineage, the ceiling is set by what one adapter can carry, and both sex and selection can only move a lineage toward that ceiling faster. Selection spreads the best genome; recombination assembles it earlier; neither raises it. The Fisher–Muller advantage in this population is a speed advantage, now shown with and without differential reproduction. Falsifier for the null (not triggered): culled declinable above culled never-merge in a majority of seeds by more than the seed-to-seed spread (~0.02). What would change the prediction is a curriculum in which skills are not guaranteed to every lineage (a lineage that never learns a family can only obtain it by merging), which is a different experiment.