Narrative Flattening: How Post-Training Compresses Thematic, Affective, and Stylistic Variation in LLM Fiction

In three linesStudy of four OLMo 32B checkpoints showing post-training (SFT, DPO, RLVR) compresses narrative variation by reducing thematic transitions, emotional intensity, and stylistic diversity. The 'narrative flattening' effect is stronger on professional literary fiction than on public-platform stories.

Summary generated by Claude — human-verified