FriendBench: Benchmarking Dyadic Familiarity Inference in Humans and Multimodal Large Language Models

Jeffrey M. Girard, Jason Zheng, Jacqueline Romero Vertino, Antony D’Avirro, Benjamin Peloquin


Abstract
Reading a social situation often depends on behavior, not words alone. We introduce FriendBench, a benchmark for inferring whether two people are already familiar or are meeting as strangers, from a 20-second clip of a dyadic ice-breaker conversation. Every pair answers the same type of prompt, so only the manner of interaction can reveal the answer. Across text, audio, and video, we compare 26 models from seven companies against matched human panels over 96 balanced dyads. The best model and the human crowd are statistically indistinguishable on accuracy in every modality, but reach it differently: humans stay balanced across the two answers, while the strongest models favor "stranger." This is a difference in effective prior, not in discrimination. Richer channels help both unequally, and only humans gain from visible behavior on top of speech. We release the stimuli, human ratings, and model predictions.
Anthology ID:
2026.mint-1.14
Volume:
Proceedings of the 1st Workshop on Multimodal Interaction in Face-to-Face Dialogue
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Esam Ghaleb, Ece Takmaz, Diego Frassinelli, Bulat Khaertdinov, Raquel Fernández, Zerrin Yumak, Asli Ozyurek
Venues:
MINT | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
127–143
Language:
URL:
https://aclanthology.org/2026.mint-1.14/
DOI:
Bibkey:
Cite (ACL):
Jeffrey M. Girard, Jason Zheng, Jacqueline Romero Vertino, Antony D’Avirro, and Benjamin Peloquin. 2026. FriendBench: Benchmarking Dyadic Familiarity Inference in Humans and Multimodal Large Language Models. In Proceedings of the 1st Workshop on Multimodal Interaction in Face-to-Face Dialogue, pages 127–143, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
FriendBench: Benchmarking Dyadic Familiarity Inference in Humans and Multimodal Large Language Models (Girard et al., MINT 2026)
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PDF:
https://aclanthology.org/2026.mint-1.14.pdf