Unveiling gender bias in LLM-generated hero and heroine narratives

This article investigates gender bias in narratives generated by Large Language Models (LLMs) through a two-phase study. Building on our existing work in narrative generation, we employ a structured methodology to analyze the influence of protagonist gender on both the generation and classification of fictional stories. In Phase 1, factual narratives were generated using six LLMs, guided by predefined narrative structures (Hero’s Journey and Heroine’s Journey). Gender bias was quantified through specialized metrics and statistical analyses, revealing significant disparities in protagonist gender distribution and associations with narrative archetypes. In Phase 2, counterfactual narratives were constructed by altering the protagonists’ genders while preserving all other narrative elements. These narratives were then classified by the same LLMs to assess how gender influences their interpretation of narrative structures. Results indicate that LLMs exhibit difficulty in disentangling the protagonist’s gender from the narrative structure, often using gender as a heuristic to classify stories. Male protagonists in emotionally driven narratives were frequently misclassified as following the Heroine’s Journey, while female protagonists in logic-driven conflicts were misclassified as adhering to the Hero’s Journey. These findings provide empirical evidence of embedded gender biases in LLM-generated narratives, highlighting the need for bias mitigation strategies in AI-driven storytelling to promote diversity and inclusivity in computational narrative generation. • A structured two-phase study investigates gender bias in LLM-generated narratives. • LLMs exhibit significant gender imbalances in protagonist representation and associate gender with specific narrative structures. • Counterfactual estimation reveals systematic misclassifications based on protagonist gender within narrative structure. • Findings highlight the need for bias mitigation strategies in LLM-based storytelling systems.