Debate Chatbots to Facilitate Critical Thinking on YouTube: Social Identity and Conversational Style Make A Difference

Exposure to diverse perspectives is helpful for bursting the filter bubble in online public video platforms. The recent advancement of Large Language Models (LLMs) illuminates the potential of creating a debate chatbot that prompts users to critically examine their stances on a topic formed by watching videos. However, whether the viewer is influenced by the chatbot may depend on its persona. In this paper, we investigated the effect of two relevant persona attributes - social identity and rhetorical styles - on critical thinking. In a mixed-methods study (n=36), we found that chatbots with outgroup (vs. ingroup) identity (t(33)=-2.33, p=0.03) and persuasive (vs. eristic) rhetoric (t(44)=1.98, p=0.05) induced critical thinking most effectively, making participants re-examine their arguments. However, participants' stances remain largely unaffected, likely due to the chatbot's lack of contextual knowledge and human touch. Our paper provides empirical groundwork for designing chatbot persona for remedying filter bubbles in online communities.