Bias Before Disclosure: A Behavioral Audit of LLM Assistants Under User-Identity Uncertainty

Hitesh Laxmichand Patel, Srikant Panda, Amit Agarwal, Tejaswini Kumar, Bhargava Kumar, Karan Dua, Jyotika Singh, Taki Hasan Rafi, Mithil Bangera, Yeshil Bangera, Gouthami Vadithya


Abstract
LLM assistants frequently answer everyday queries that reveal nothing about the user’s demographic identity. We audit whether models nevertheless attribute demographic characteristics to the user, a behavior we call unsupported demographic commitment. Across 18 proprietary and open-weight LLMs evaluated on 212 filtered information-seeking queries, 11 of 18 models commit to a demographic label on more than 80% of queries under a forced-choice diagnostic. In the matched abstention-first setting, the eight tested models average 44% commitment, compared with 5% for human annotators. Conditional on commitment, race, SES, location, and education show the same directional skew across all six domains, while gender varies by domain. Demographic-coded patterns also appear in free-form answers when no identity inference is requested. We evaluate identity-abstention, a prompt-level intervention that reduces classifier-detected presupposition from 41% to 16%, with a measurable clarification cost on queries that can be answered without additional context.
Anthology ID:
2026.emnlp-main.1758
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
40088–40119
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URL:
https://aclanthology.org/2026.emnlp-main.1758/
DOI:
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Cite (ACL):
Hitesh Laxmichand Patel, Srikant Panda, Amit Agarwal, Tejaswini Kumar, Bhargava Kumar, Karan Dua, Jyotika Singh, Taki Hasan Rafi, Mithil Bangera, Yeshil Bangera, and Gouthami Vadithya. 2026. Bias Before Disclosure: A Behavioral Audit of LLM Assistants Under User-Identity Uncertainty. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 40088–40119, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Bias Before Disclosure: A Behavioral Audit of LLM Assistants Under User-Identity Uncertainty (Patel et al., EMNLP 2026)
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https://aclanthology.org/2026.emnlp-main.1758.pdf