Flexible Thinking for Multimodal Emotional Support Conversation via Reinforcement Learning

Emotional Support Conversation (ESC) systems aim to alleviate user distress. However, current Chain-of-Thought based ESC methods often employ rigid, text-only reasoning, limiting adaptability in dynamic, multimodal interactions and introducing reasoning noise that degrades support quality. To address this, we introduce "Flexible Thinking" for multimodal ESC, enabling models to adaptively select contextually relevant thinking aspects: Visual Scene, Emotion, Situation, and Response Strategy. We first construct training data by manually curating flexible thinking demonstrations on the MESC dataset, then using a Multimodal Large Language Model to synthesize these processes for the full training set. Then, we propose FIRES, a framework integrating Supervised Fine-Tuning (SFT) for initial learning with Reinforcement Learning for refinement. This two-stage approach helps FIRES transcend SFT's generalization limits and, crucially, directly links thinking processes to response quality via tailored rewards, moving beyond imitating potentially imperfect synthetic data. Experiments on MESC and EMOTyDA datasets demonstrate FIRES's effectiveness and generalizability in fostering higher-quality emotional support responses through adaptive reasoning.