Mind the (DH) Gap! A Contrast in Risky Choices Between Reasoning and Conversational LLMs

Luise Ge, Yongyan Zhang, Yevgeniy Vorobeychik


Abstract
The use of large language models either as decision support systems, or in agentic workflows, is rapidly transforming the digital ecosystem. However, the understanding of LLM decision-making under uncertainty remains limited. We initiate a comparative study of LLM risky choices along two dimensions: (1) prospect representation (explicit vs. experience-based) and (2) decision rationale (explanation). Our study, which involves 20 frontier and open LLMs, is complemented by a matched human subjects experiment, which provides one reference point, while an expected payoff maximizing rational agent model provides another. We find that LLMs cluster into two categories: reasoning models (RMs) and conversational models (CMs). RMs tend towards rational behavior, are insensitive to the order of prospects, gain/loss framing, and explanations, and behave similarly whether prospects are explicit or presented via experience history. CMs are significantly less rational, slightly more human-like, sensitive to prospect ordering, framing, and explanation, and exhibit a large description-history gap. Paired comparisons of open LLMs suggest that a key factor differentiating RMs and CMs is training for mathematical reasoning.
Anthology ID:
2026.acl-long.479
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
10503–10525
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.479/
DOI:
Bibkey:
Cite (ACL):
Luise Ge, Yongyan Zhang, and Yevgeniy Vorobeychik. 2026. Mind the (DH) Gap! A Contrast in Risky Choices Between Reasoning and Conversational LLMs. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 10503–10525, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Mind the (DH) Gap! A Contrast in Risky Choices Between Reasoning and Conversational LLMs (Ge et al., ACL 2026)
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PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.479.pdf
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 2026.acl-long.479.checklist.pdf