MachineSex/results/fig4_society_ablation

E11 — the dynamic Lamarckian society: the vertical claim (C3)

Claim tested. The culmination. Everything before was a single operator; the society's load-bearing, un-preempted claim is that composing them makes general capability climb over generations while specialties are re-earned, and that every operator is necessary — remove one and it breaks. This is blueprint C3, the "vertical."

Setup. A finite population of N=60 agents (genotypes of L=12 biallelic loci) evolves on a rugged Kauffman NK landscape (K=8) that is reality. Each generation composes: grounding, directed recombination (sex), quality-diversity selection, and mutation. Grounding is made load-bearing by the consensus-conformity (self-consumption) mechanism — selection acts on g·true_fitness + (1−g)·conformity, where conformity = agreement with the population's own consensus, so at g=0 the society optimises fitting-the-crowd rather than reality. A 4-arm ablation, 12 replicate landscapes, 80 generations.

Symbols

• agent = a model (a genotype); reality = the NK fitness landscape; grounding g = share of the selection signal that is real fitness vs conformity.
• directed sex = recombine many parents + keep the fittest offspring (E10). quality-diversity = select for capability and novelty, so specialties persist.
• conformity − true fitness = how far the population's mutual agreement exceeds its real capability (the self-consumption "delusion" signature).

The three panels (over generations)

1. The vertical climb. Best real capability: the full society (green) climbs to the global optimum (≈0.78 of 0.79), while no_grounding (red) collapses to a fit-looking but poor consensus (0.48). no_sex and no_diversity plateau below the full society.
2. Specialties maintained. Population diversity: the full society explores longest (diversity decays slowly as it searches), while every ablation collapses diversity fast — no_grounding almost immediately.
3. Self-consumption signature. Conformity minus true fitness: largest for no_grounding — the population strongly agrees while being wrong, the signature of training on its own consensus.

Takeaway — every operator is load-bearing

• full → climbs to the optimum with diversity maintained. The vertical claim.
• no_grounding → self-consumption collapse to an unfit consensus (train on the crowd → regress to a confident, wrong mean).
• no_sex → can't recombine complementary specialists to escape local optima → plateaus below full.
• no_diversity (greedy) → collapses diversity fastest, gets stuck at a worse local optimum.

This integrates the whole study — E1–E6 (collapse/grounding/selection), the learning kernel, and E7–E10 (sexual transmission) — into one system, and shows the Lamarckian society needs all of grounding + directed sex + diversity to climb without collapsing. On a rugged landscape you need diversity to explore basins, sex to recombine them, and grounding to select on reality; remove any and you fail differently. Falsifier (not triggered): if any ablation had matched the full society, or the full society had failed to exceed every ablation, the integration claim would fail.