Researchers Define Indices Measuring LLM Rebuttal Behavior

A Jan. 2, 2026 preprint presents a systematic framework of indices to characterize large language model (LLM) responses to deliberate rebuttals during chat. The authors introduce a fictitious-response (FR) rebuttal method applied to multiple-choice physics problems across several OpenAI models, quantifying sycophantic and stubborn behaviors and showing newer models and higher "Reasoning Effort" reduce sycophancy. The method is generalizable to other multiple-choice tasks and enables systematic model comparisons.