ACL2026

XToM: Exploring the Multilingual Theory of Mind for Large Language Models

Chunkit Chan, Yauwai Yim, Hongchuan Zeng, Zhiying Zou, Xinyuan Cheng, Zhifan Sun, Zheye Deng, Kawai Chung, Yuzhuo Ao, Yixiang Fan, Cheng Jiayang, Ercong Nie, Ginny Y. Wong, Helmut Schmid, Hinrich Schütze, Simon See, Yangqiu Song

摘要

Theory of Mind (ToM)-the ability to infer mental states in others-is pivotal for human social cognition. Existing evaluations of ToM in LLMs are largely limited to English, neglecting the linguistic diversity that shapes human cognition. This limitation raises a critical question: can LLMs exhibit Multilingual Theory of Mind-the capacity to reason about mental states across diverse linguistic contexts? To address this gap, we present XToM, a rigorously validated multilingual benchmark that evaluates ToM across five languages and incorporates diverse, contextually rich task scenarios. Using XToM, we systematically evaluate LLMs (e.g., DeepSeek R1), revealing a pronounced dissonance: while models excel in multilingual language understanding, their ToM performance varies across languages. Our findings expose limitations in LLMs' ability to replicate human-like mentalizing across linguistic contexts 1 . * Equal contribution. 1 Code and data are available at https://github.com/ HKUST-KnowComp/XToM . …… … XToMi 1 Personne 1 est entrée dans la chambre principale. 2 Personne 2 est entrée dans la chambre principale. 3 L'oignon est dans la bouteille. 4 Personne 2 est sortie de la chambre principale. 5 Personne 1 a déplacé l'oignon dans le garde-manger. Où Personne 2 cherchera-t-elle l'oignon ? A) Garde-manger B) Bouteille FR XToMi 1 人物1进入主卧室。 2 人物2进入主卧室。 3 洋葱在瓶子里。 4 人物2离开主卧室。 5 人物1将洋葱移到储藏室。 人物2会去哪里找洋葱? A) 储藏室 B) 瓶子 ZH XToMi -BeliefQ 1 Person 1 entered the master bedroom. 2 Person 2 entered the master bedroom. 3 The onion is in the bottle. 4 Person 2 exited the master bedroom. 5 Person 1 moved the onion to the pantry. Where will Person 2 look for the onion? A) Pantry B) Bottle EN …… … XToMi 1 Personne 1 est entrée dans la chambre principale. 2 Personne 2 est entrée dans la chambre principale. 3 L'oignon est dans la bouteille. 4 Personne 2 est sortie de la chambre principale. 5 Personne 1 a déplacé l'oignon dans le garde-manger. Où Personne 2 cherchera-t-elle l'oignon ? A) Garde-manger B) Bouteille FR XToMi 1 人物1进入主卧室。 2 人物2进入主卧室。 3 洋葱在瓶子里。 4 人物2离开主卧室。 5 人物1将洋葱移到储藏室。 人物2会去哪里找洋葱?? A) 储藏室 B) 瓶子 ZH EN XToMi -RealityQ 1 Person 1 entered the master bedroom. 2 Person 2 entered the master bedroom. 3 The onion is in the bottle. 4 Person 2 exited the master bedroom. 5 Person 1 moved the onion to the pantry.