Evaluating Personality Traits in Large Language Models: Insights from Psychological Questionnaires
Pranav Bhandari, Usman Naseem, Amitava Datta, Nicolas Fay, Mehwish Nasim
TL;DR
Problem: Do LLMs exhibit human-like personality traits, and can psychometric tools meaningfully quantify them without data leakage? Approach: The authors apply restructured Big Five questionnaires to multiple LLMs (e.g., GPT-4, GPT-4o-mini, Llama variants), use randomized prompt sequences, and compute consistency via the coefficient of variation across 100 runs. Contributions: They report distinct personality profiles across models, with higher Openness, Conscientiousness, and Agreeableness, and model-type-specific dimensional dominance (e.g., Agreeableness in OpenAI models; Openness or Conscientiousness in Llama variants). Significance: The study provides a rigorous framework for interpreting LLM behavior through psychometrics and highlights the need for careful questionnaire design to avoid contamination and misinterpretation.
Abstract
Psychological assessment tools have long helped humans understand behavioural patterns. While Large Language Models (LLMs) can generate content comparable to that of humans, we explore whether they exhibit personality traits. To this end, this work applies psychological tools to LLMs in diverse scenarios to generate personality profiles. Using established trait-based questionnaires such as the Big Five Inventory and by addressing the possibility of training data contamination, we examine the dimensional variability and dominance of LLMs across five core personality dimensions: Openness, Conscientiousness, Extraversion, Agreeableness, and Neuroticism. Our findings reveal that LLMs exhibit unique dominant traits, varying characteristics, and distinct personality profiles even within the same family of models.
