🤖 AI Summary
This study proposes a “collective realism” evaluation paradigm to assess whether political discourse generated by large language models during crisis events reflects the social realities of actual populations, rather than merely optimizing for textual fluency. Leveraging a million-scale paired corpus spanning nine major crises, the authors compare real social media discourse with model-generated outputs across four dimensions: emotional intensity, structural regularity, lexical ideological framing, and cross-event dependency. They introduce the “Caricature Gap” metric to quantify systematic distortions in synthetic discourse at the population level. Findings reveal that while model-generated texts are fluent, they exhibit more concentrated negativity, greater structural regularity, and more abstract lexical choices—deviations that are especially pronounced in decentralized crises—thereby exposing the limitations of conventional sentence-level evaluation frameworks.
📝 Abstract
Large Language Models (LLMs) can generate fluent political text at scale, raising concerns about synthetic discourse during crises and social conflict. Existing AI-text detection often focuses on sentence-level cues such as perplexity, burstiness, or token irregularities, but these signals may weaken as generative systems improve. We instead adopt a Computational Social Science perspective and ask whether synthetic political discourse behaves like an observed online population. We construct a paired corpus of 1,789,406 posts across nine crisis events: COVID-19, the Jan. 6 Capitol attack, the 2020 and 2024 U.S. elections, Dobbs/Roe v. Wade, the 2020 BLM protests, U.S. midterms, the Utah shooting, and the U.S.-Iran war. For each event, we compare observed discourse from social platforms with synthetic discourse generated for the same context. We evaluate four dimensions: emotional intensity, structural regularity, lexical-ideological framing, and cross-event dependency, using mean gaps and dispersion evidence. Across events, synthetic discourse is fluent but population-level unrealistic. It is generally more negative and less dispersed in sentiment, structurally more regular, and lexically more abstract than observed discourse. Observed discourse instead shows broader emotional variation, longer-tailed structural distributions, and more context-specific, colloquial lexical markers. These differences are event-dependent: larger for fast-moving, decentralized crises and smaller for formal or institutionally mediated events. We summarize them with a simple event-level measure, the Caricature Gap. Our findings suggest that the main limitation of synthetic political discourse is not grammar or fluency, but reduced population realism. Population-level auditing complements traditional text-detection and provides a CSS framework for evaluating the social realism of generated discourse.