OpenAI hasn’t provided an explanation for o1’s strange behavior — or even acknowledged it. So what might be going on?

Well, AI experts aren’t sure. But they have a few theories.

Several on X, including Hugging Face CEO Clément Delangue, alluded to the fact that reasoning models like o1 are trained on data sets containing a lot of Chinese characters. Ted Xiao, a researcher at Google DeepMind, claimed that companies including OpenAI use third-party Chinese data labeling services, and that o1 switching to Chinese is an example of “Chinese linguistic influence on reasoning.”