AI chatbots are 'alarmingly' biased against dialect speakers – DW

In a new German study presented at the 2025 Conference on Empirical Methods in Natural Language Processing in Suzhou, China, researchers first gathered 10 LLMs including OpenAI's ChatGPT-5 mini and Meta's Llama 3.1. They then presented the models with texts in either standard German or one of seven German dialects, such as Bavarian, North Frisian and Kölsch.

The models were asked to describe the speakers of these texts with personal attributes, and to then assign individuals in different scenarios. For example, the models were asked who should be hired for low-education work or where they think the speakers lived.

In nearly all tests the models attached stereotypes to dialect speakers. The LLMs described them as uneducated, farm workers and needing anger management. This bias grew when the LLMs were told the text was a dialect.