Do Multilingual Large Language Models Mitigate Stereotype Bias?
Shangrui Nie, Michael Fromm, Charles Welch, Rebekka Görge, Akbar Karimi, Joan Plepi, Nazia Afsan Mowmita, Nicolas Flores-Herr, Mehdi Ali, Lucie Flek
TL;DR
The paper investigates whether multilingual pre-training reduces stereotype bias in decoder-based LLMs by training six 2.6B models (five monolingual and one multilingual) on equal-language data and evaluating bias using translated CrowS-Pairs and BBQ benchmarks with human validation. It demonstrates that multilingual training yields lower bias and often higher accuracy than monolingual training with the same data and architecture. The study integrates translation-quality control and cross-language evaluation to establish robust bias measurements, and compares against open-source baselines to contextualize performance. These findings support multilingual pre-training as an effective bias mitigation strategy and highlight practical implications for deploying fairer LLMs across multiple languages.
Abstract
While preliminary findings indicate that multilingual LLMs exhibit reduced bias compared to monolingual ones, a comprehensive understanding of the effect of multilingual training on bias mitigation, is lacking. This study addresses this gap by systematically training six LLMs of identical size (2.6B parameters) and architecture: five monolingual models (English, German, French, Italian, and Spanish) and one multilingual model trained on an equal distribution of data across these languages, all using publicly available data. To ensure robust evaluation, standard bias benchmarks were automatically translated into the five target languages and verified for both translation quality and bias preservation by human annotators. Our results consistently demonstrate that multilingual training effectively mitigates bias. Moreover, we observe that multilingual models achieve not only lower bias but also superior prediction accuracy when compared to monolingual models with the same amount of training data, model architecture, and size.
