AI-generated impersonations of political figures are judged by members of the public to be more authentic, relevant, and coherent than the speakers' actual debate responses, according to a new study published July 1, 2026 in the open-access journal PLOS One by Steffen Herbold of the University of Passau, Germany, and colleagues.
Modern generative AI models like GPT, Claude, and Gemini have been shown to be able to role play, mimic the linguistic pattern of authors, create content that reflects general political identity, and assume the role of a domain expert.
In the new study, researchers used GPT-4 Turbo to generate impersonated responses to audience questions drawn from 30 episodes of BBC1's Question Time. They prompted the AI model with the Wikipedia biographies of 112 different public figures and asked for impersonated responses of the figures. A representative sample of 948 UK adults then rated both the original and AI-generated responses for authenticity, coherence, and relevance, with some participants viewing single responses and others comparing original and impersonated responses side by side.
Overall, participants rated the AI-generated responses as more authentic, coherent, and relevant than the real ones, with the differences statistically significant in every comparison. Despite measurable linguistic differences between the two sets of responses, including a greater range of vocabulary and fewer epistemic markers (such as "I think") in the AI-generated text, these stylistic differences did not affect participants' authenticity judgments. Around half of the responses considered the content of the original and impersonated responses to differ. Further analysis on a subset of responses suggested that the AI-generated response addressed the question while the real speaker did not, or the two responses expressed different stances altogether.
Since the study examined a single debate format from one country and used one AI model, it may not be widely applicable to all settings. While the researchers ruled out response length and grammatical errors as explanations for their findings, there could be other unobserved factors influencing participants' ratings of the responses.
However, the authors conclude that AI can be used to generate impersonated political content that is not just believable but rated as more authentic than the real thing, raising concerns about the potential for targeted misinformation campaigns against specific public figures.
Prof. Dr. Steffen Herbold adds: "Our study conclusively shows that humans think AI-generated debate content is more authentic than what the actual well-known public persons said. This shows the enormous misinformation potential of AI that society must be aware of to critically judge any written information and prevent the unmitigated spread of AI generated misinformation. Our representative survey also shows an overwhelming desire for transparency: people want to know when AI was used and they want to have information on how AI was trained publicly available."
Prof. Dr. Annette Hautli-Janisz adds: "Interestingly, the linguistic surface is not necessarily different between original and impersonated responses - for instance, sentence complexity is comparable across both sources. But lexical cues like epistemic markers (e.g., 'I think') are significantly more frequent in original responses. The overlap between the question and the response text is significantly higher in generated responses, indicating that the panel members do not always address the question directly."
In your coverage, please use this URL to provide access to the freely available article in PLOS One: https://plos.io/3Sl35Pa
Citation: Herbold S, Trautsch A, Kikteva Z, Hautli-Janisz A (2026) LLM-impersonated debate contributions are more authentic, relevant and coherent than their original: A representative study using BBC1's Question Time. PLoS One 21(7): e0347757. https://doi.org/10.1371/journal.pone.0347757
Author countries: Germany.
Funding: A.H. work was partially funded by the VolkswagenStiftung under grant Az. 98544 'Deliberation Laboratory' URL: https://www.volkswagenstiftung.de/ The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
