Measuring Emergent Coordination in Multi-Agent LLMs via Information Decomposition

Christoph Riedl (Northeastern) · ICLR 2026 · Ten GPT-4.1 agents, group binary search
arXiv 2510.05174
10GPT-4.1 agents, T=1
600runs: 200 groups × 3 conditions
3.5%groups significant alone (chance 5%)
~1e-16Fisher pooled p

Group binary search Illustrative

Each agent guesses 0–50; guesses must sum to a hidden target. Only "too high / too low" is shared. Target 237 is chosen here for illustration.

Why identical agents fail

Identical guesses give sums that are multiples of 10. Complementary offsets are needed for other targets.

Partial information decomposition

Information that sources X1, X2 carry about target Y splits into four atoms. Textbook examples

Which redundancy definition?

Synergy depends on the chosen redundancy measure.

Three prompt conditions

Click a layer stack. The clean ToM effect is ToM vs Persona.

Three instruments on short trajectories

Null baselines Reported design

Score = observed − median of shuffled scores. Click a stage.

Preliminary experiment: 7,150 runs Reported

Odds ratios for success (log axis). No intervals reported in the discussion.

Reported results Reported

Significance heatmap (−log10 p)

Hover a cell. Colour scales −log10 p, capped at 16.

Hover a cell.

Pooled signal vs. individual groups

200 groups. Reported: 3.5% clear p<0.05 alone; chance gives about 5% (~10). Which groups is not reported. Illustrative layout

Two questions, two tests Illustrative

Link to performance Reported

Synergy × redundancy interaction: β 0.24, p 0.014 (27% log-odds amplification). Mediation of ToM → success via synergy:

Controls the discussion would want Suggested, not in paper

References

  1. Emergent Coordination in Multi-Agent Language Models — Riedl (arXiv 2510.05174)
  2. Nonnegative Decomposition of Multivariate Information — Williams, Beer, 2010
  3. Reconciling emergences — Rosas et al., 2020
  4. Greater than the parts — Mediano et al., 2022
  5. Quantifying High-order Interdependencies — Rosas et al., 2019
  6. AutoGen — Wu et al., 2023
  7. MetaGPT — Hong et al., 2024
  8. AgentVerse — Chen et al., 2023
  9. Collective Intelligence Factor in Human Groups — Woolley et al., 2010
  10. Machine Theory of Mind — Rabinowitz et al., 2018
  11. Theory of Mind May Have Spontaneously Emerged in LLMs — Kosinski, 2023
  12. Generative Agents — Park et al., 2023
  13. Cicero (Diplomacy) — Meta FAIR et al., 2022
  14. Quantifying unique information (I_BROJA) — Bertschinger et al., 2014
  15. Integrated information decomposition (ΦID) — Mediano et al., 2025
  16. Emergence of specialized roles within groups — Goldstone et al., 2024
  17. Quantifying collective intelligence in human groups — Riedl et al., 2021
  18. Why do multi-agent LLM systems fail? — Cemri et al., 2025
  19. Emergent social conventions — Ashery et al., 2025
  20. Corrupted by reasoning — Piedrahita et al., 2025
  21. Clever Hans or neural theory of mind? — Shapira et al., 2024
  22. More agents is all you need — Li et al., 2024