Evaluating LLMs for Detecting Demographic-Targeted Social Bias: A Comprehensive Benchmark Study

Ayan Majumdar, Feihao Chen, Jinghui Li, Xiaozhen Wang


Abstract
Large-scale web-scraped text corpora used to train general-purpose AI models often contain harmful demographic-targeted social biases, creating a regulatory need for data auditing and developing scalable bias-detection methods. Although prior work has investigated biases in text datasets and related detection methods, these studies remain narrow in scope. They typically focus on a single content type (e.g., hate speech), cover limited demographic axes, overlook biases affecting multiple demographics simultaneously, and analyze limited techniques. Consequently, practitioners lack a holistic understanding of the strengths and limitations of recent large language models (LLMs) for automated bias detection. In this study, we conduct a comprehensive benchmark study on English texts to assess the ability of LLMs in detecting demographic-targeted social biases. To align with regulatory requirements, we frame bias detection as a multi-label task of detecting targeted identities using a demographic-focused taxonomy. We then systematically evaluate models across scales and techniques, including prompting, in-context learning, and fine-tuning. Using twelve datasets spanning diverse content types and demographics, our study demonstrates the promise of fine-tuned smaller models for scalable detection. However, our analyses also expose persistent gaps across identity axes and multi-demographic targeted biases, underscoring the need for more effective and scalable detection frameworks.
Anthology ID:
2026.iaai-1.5
Volume:
Proceedings of the Second Workshop of Identity Aware AI
Month:
May
Year:
2026
Address:
Palma de Mallorca, Spain
Editors:
A Pranav, Valerio Basile, Neele Falk, David Jurgens, Gabriella Lapesa, Anne Lauscher, Soda Marem Lo
Venues:
iaai | WS
SIG:
Publisher:
European Language Resources Association
Note:
Pages:
47–65
Language:
External URL:
https://lrec.elra.info/lrec2026-ws-iaai-05
DOI:
10.63317/3jejtg2hfj3t
Bibkey:
Cite (ACL):
Ayan Majumdar, Feihao Chen, Jinghui Li, and Xiaozhen Wang. 2026. Evaluating LLMs for Detecting Demographic-Targeted Social Bias: A Comprehensive Benchmark Study. In Proceedings of the Second Workshop of Identity Aware AI, pages 47–65, Palma de Mallorca, Spain. European Language Resources Association.
Cite (Informal):
Evaluating LLMs for Detecting Demographic-Targeted Social Bias: A Comprehensive Benchmark Study (Majumdar et al., iaai 2026)
Copy Citation: