@inproceedings{joshi-etal-2025-improving,
    title = "Improving Language Model Personas via Rationalization with Psychological Scaffolds",
    author = "Joshi, Brihi  and
      Ren, Xiang  and
      Swayamdipta, Swabha  and
      Koncel-Kedziorski, Rik  and
      Paek, Tim",
    editor = "Christodoulopoulos, Christos  and
      Chakraborty, Tanmoy  and
      Rose, Carolyn  and
      Peng, Violet",
    booktitle = "Findings of the Association for Computational Linguistics: EMNLP 2025",
    month = nov,
    year = "2025",
    address = "Suzhou, China",
    publisher = "Association for Computational Linguistics",
    url = "https://preview.aclanthology.org/author-page-yu-wang-polytechnic/2025.findings-emnlp.1187/",
    doi = "10.18653/v1/2025.findings-emnlp.1187",
    pages = "21747--21770",
    ISBN = "979-8-89176-335-7",
    abstract = "Language models prompted with a user description or persona have been used to predict the user{'}s preferences and opinions. However, existing approaches to building personas mostly rely on a user{'}s demographic attributes and/or prior judgments, but not on any underlying reasoning behind a user{'}s judgments. We introduce PB{\&}J (Psychology of Behavior and Judgments), a framework that improves LM personas by incorporating potential rationales for why the user could have made a certain judgment. Our rationales are generated by a language model to explicitly reason about a user{'}s behavior on the basis of their experiences, personality traits, or beliefs. Our method employs psychological scaffolds: structured frameworks such as the Big 5 Personality Traits or Primal World Beliefs to help ground the generated rationales in existing theories. Experiments on public opinion and movie preference prediction tasks demonstrate that language model personas augmented with PB{\&}J rationales consistently outperform personas conditioned only on user demographics and / or judgments, including those that use a model{'}s default chain-of-thought, which is not grounded in psychological theories. Additionally, our PB{\&}J personas perform competitively with those using human-written rationales, suggesting the potential value of synthetic rationales guided by existing theories."
}