Beyond Sally-Anne: Evaluating Theory of Mind in Large Language Models using Epistemic Schelling Points

Roberta Rocca, Sami Boukortt, Geoff Keeling, Winnie Street


Abstract
Text-based evaluations of Theory of Mind (ToM) in Large Language Models (LLMs) often involve cognitive tests akin to the Sally-Anne task that can be gamed due to exposure to relevantly similar tasks in pre-training and do not obviously test models’ functional ToM abilities in ways that generalize to naturalistic settings. To address these issues, we introduce the Epistemic (A)symmetry Schelling Task (EAST), a two-player dialogue game designed to benchmark robust and generalizable ToM abilities. By requiring LLM-LLM dyads to independently converge on semantic Schelling points under varying states of epistemic transparency, we evaluate whether models can robustly apply ToM to achieve coordination. Our results reveal a significant capability gap in functional social reasoning, with only frontier models successfully navigating the varying epistemic demands of the tasks. Analysis of reasoning traces shows that coordination failures are primarily driven by epistemic tracking errors, such as conflating private knowledge with mutual knowledge. Despite high performance on traditional static benchmarks, our study shows that robust social reasoning and epistemic tracking remain a critical bottleneck, providing concrete targets for future LLM evaluation and development.
Anthology ID:
2026.lmplayschool-1.1
Volume:
The Proceedings of Improving Language Models through Learning from Dialogue Game Interaction
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Alessandro Suglia, Mario Giulianelli, David Schlangen, Raffaella Bernardi, Raquel Fernández, Sherzod Hakimov, Sabrina McCallum, Davide Mazzaccara, Dieu-Thu Le, Oliver Lemon, Alexander Koller
Venues:
LM Playschool | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
1–18
Language:
URL:
https://aclanthology.org/2026.lmplayschool-1.1/
DOI:
Bibkey:
Cite (ACL):
Roberta Rocca, Sami Boukortt, Geoff Keeling, and Winnie Street. 2026. Beyond Sally-Anne: Evaluating Theory of Mind in Large Language Models using Epistemic Schelling Points. In The Proceedings of Improving Language Models through Learning from Dialogue Game Interaction, pages 1–18, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Beyond Sally-Anne: Evaluating Theory of Mind in Large Language Models using Epistemic Schelling Points (Rocca et al., LM Playschool 2026)
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PDF:
https://aclanthology.org/2026.lmplayschool-1.1.pdf