Divergent Minds, Convergent Baselines: A Bounded-Rationality Account of LLM-Human Strategic Behaviour
Pith reviewed 2026-07-01 16:53 UTC · model grok-4.3
The pith
LLMs reach rational play in canonical games by retrieving solutions from training corpora instead of incurring the computational bound that shifts human choices.
A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.
Core claim
For canonical games whose solutions are present in standard training corpora, LLMs retrieve and recombine corpus material, bypassing the bound that produces δ in humans. The framing extends to reasoning-distilled models through cognitive-hierarchy theory: their accessible level-k strategic reasoning is bounded by compute budget and context length rather than by the cognitive constraints that bound humans, and the δ they produce, if any, carries different structural signatures.
What carries the argument
The δ term, read as the mathematical signature of bounded computation: the gap between what an unboundedly-rational agent would compute and what a computationally bounded agent actually produces.
If this is right
- Four operational tests discriminate human-shaped δ from LLM-shaped δ.
- The magnitude of δ scales with peer-signal individuation, producing Cohen's d at least 0.5 between named-opponent and aggregate-opponent conditions.
- Reasoning-distilled models produce δ with different structural signatures from human δ because their bounds arise from compute budget and context length.
- The substitution of LLMs for humans in strategic experiments will continue to fail under current alignment methods.
Where Pith is reading between the lines
- In games whose solutions are absent from training data, LLMs should produce δ signatures closer to those observed in humans.
- Experiments could be redesigned around novel or paraphrased games to reduce corpus leakage when LLMs are used as subject proxies.
- The moderator prediction supplies a quantitative threshold that could be checked directly in any decision environment that varies opponent identifiability.
Load-bearing premise
The observed gap between LLM and human choices stems from LLMs accessing pre-existing corpus solutions for canonical games rather than facing equivalent computational bounds.
What would settle it
Running the four proposed tests (conditional dependence, distributional asymmetry, path-dependence under repetition, and paraphrase-robustness) on a canonical game with known corpus solutions and finding that LLM δ matches the structural signatures of human δ would falsify the claim that LLMs bypass the bound.
read the original abstract
Researchers have started using LLM agents in place of human subjects in behavioural and political-science experiments, often as a cheaper substitute for laboratory pools. The substitution does not hold up in strategic settings: humans and LLMs reliably make different choices, and neither fine-tuning on human response data nor persona conditioning has closed the gap. The behavioural-economics literature has, since Simon's introduction of bounded rationality, modelled human strategic behaviour as a classical baseline plus an additive correction term $\delta$. The framework proposed here reads $\delta$ as the mathematical signature of bounded computation: the gap between what an unboundedly-rational agent would compute and what a computationally bounded agent actually produces. For canonical games whose solutions are present in standard training corpora, LLMs retrieve and recombine corpus material, bypassing the bound that produces $\delta$ in humans. The framing extends to reasoning-distilled models through cognitive-hierarchy theory: their accessible level-$k$ strategic reasoning is bounded by compute budget and context length rather than by the cognitive constraints that bound humans, and the $\delta$ they produce, if any, carries different structural signatures. Four operational tests (conditional dependence, distributional asymmetry, path-dependence under repetition, and paraphrase-robustness) are proposed to discriminate human-shaped $\delta$ from LLM-shaped $\delta$. A moderator prediction is that $|\delta|$ scales with peer-signal individuation in the decision environment, with a quantitative bound of Cohen's $d \geq 0.5$ between named-opponent and aggregate-opponent settings.
Editorial analysis
A structured set of objections, weighed in public.
Referee Report
Summary. The manuscript proposes a bounded-rationality framework in which the correction term δ represents the gap between unbounded-rational and computationally bounded output. It argues that LLMs bypass this δ for canonical games by retrieving and recombining solutions present in training corpora, extends the account to reasoning-distilled models via cognitive-hierarchy considerations, proposes four operational tests (conditional dependence, distributional asymmetry, path-dependence under repetition, and paraphrase-robustness) to discriminate human-shaped from LLM-shaped δ, and advances a moderator prediction that |δ| scales with peer-signal individuation (Cohen's d ≥ 0.5).
Significance. If the proposed tests prove diagnostic, the framework would supply a principled basis for deciding when LLM agents can substitute for human subjects in strategic experiments and would distinguish retrieval signatures from genuine computational bounds. The explicit listing of falsifiable tests is a constructive element of the proposal.
major comments (2)
- [Abstract] Abstract: the moderator prediction asserts a quantitative bound of Cohen's d ≥ 0.5 between named-opponent and aggregate-opponent settings without derivation, external benchmark, or supporting calculation; this bound is load-bearing for the claimed empirical testability of the framework.
- [Framework (reasoning-distilled models)] Section on the framework extending to reasoning-distilled models: the claim that any δ produced by such models carries different structural signatures because their level-k reasoning is bounded by compute budget and context length (rather than human cognitive constraints) is stated without concrete formal distinction or illustrative example, which underpins the extension of the theory beyond standard LLMs.
minor comments (1)
- The four tests are enumerated but their precise operational definitions (e.g., how conditional dependence would be measured in a given game) are not expanded; adding brief implementation sketches would improve clarity without altering the central proposal.
Simulated Author's Rebuttal
We thank the referee for their thoughtful review and constructive suggestions. We address the two major comments point by point below, indicating the revisions we plan to make to strengthen the manuscript.
read point-by-point responses
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Referee: [Abstract] Abstract: the moderator prediction asserts a quantitative bound of Cohen's d ≥ 0.5 between named-opponent and aggregate-opponent settings without derivation, external benchmark, or supporting calculation; this bound is load-bearing for the claimed empirical testability of the framework.
Authors: We acknowledge that the specific threshold of Cohen's d ≥ 0.5 is stated in the abstract without an accompanying derivation or external benchmark. This value was chosen as a conventional medium effect size in psychological and behavioral research to illustrate the moderator prediction's testability. To address this, we will revise the abstract to clarify that the bound is illustrative and motivated by standard effect-size conventions (e.g., Cohen, 1988), and we will add a brief derivation in the main text linking the moderator prediction to expected differences in peer-signal individuation. This revision will preserve the framework's empirical claims while providing the requested justification. revision: yes
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Referee: [Framework (reasoning-distilled models)] Section on the framework extending to reasoning-distilled models: the claim that any δ produced by such models carries different structural signatures because their level-k reasoning is bounded by compute budget and context length (rather than human cognitive constraints) is stated without concrete formal distinction or illustrative example, which underpins the extension of the theory beyond standard LLMs.
Authors: We agree that the extension to reasoning-distilled models requires a more explicit formal distinction and example to be fully convincing. In the revised version, we will introduce a short subsection or paragraph providing a concrete example using the p-beauty contest game. We will contrast how a standard LLM might retrieve the Nash equilibrium (bypassing δ) with how a reasoning-distilled model, limited by context length to lower k levels, produces a δ with different properties (e.g., sensitivity to compute budget rather than cognitive load). This will include a formal note distinguishing the bounding mechanisms: human cognitive constraints vs. model-specific resource limits. We believe this addition will solidify the theoretical extension. revision: yes
Circularity Check
No significant circularity detected
full rationale
The manuscript is a conceptual proposal that reinterprets the existing bounded-rationality term δ (defined in the literature as the gap between unbounded-rational baseline and observed behavior) as a computational signature and contrasts it with LLM corpus-retrieval behavior. It advances four operational tests and one moderator prediction as hypotheses to discriminate signatures, without any internal equations, fitted parameters, or self-citations that reduce a claimed result to its own inputs by construction. The argument is therefore self-contained and relies on external empirical discrimination rather than definitional closure.
Axiom & Free-Parameter Ledger
free parameters (1)
- Cohen's d >= 0.5 moderator bound
axioms (1)
- domain assumption Human strategic behavior is a classical baseline plus additive correction δ arising from bounded computation
Reference graph
Works this paper leans on
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[1]
Aher, G., Arriaga, R. I., & Kalai, A. T. (2023). Using large language models to simulate multiple humans and replicate human subject studies. In Proceedings of the 40th International Conference on Machine Learning (ICML). arXiv:2208.10264. https://arxiv.org/abs/2208.10264 Akata, E., Schulz, L., Coda-Forno, J., Oh, S. J., Bethge, M., & Schulz, E. (2025). P...
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[2]
https://doi.org/10.1016/j.tics.2024.01.011 Mei, Q., Xie, Y., Yuan, W., & Jackson, M. O. (2024). A Turing test of whether AI chatbots are behaviorally similar to humans. Proceedings of the National Academy of Sciences, 121(9), Article e2313925121. https://doi.org/10.1073/pnas.2313925121 Mozikov, M., Severin, N., Bodishtianu, V., Glushanina, M., Baklashkin,...
discussion (0)
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