ThinkTuning: Instilling Cognitive Reflections without Distillation

TL;DR

ThinkTuning introduces a novel interactive training method that uses teacher feedback to enhance reasoning in language models, outperforming baseline approaches without relying on distillation.

Contribution

We propose ThinkTuning, a GRPO-based interactive training approach that improves reasoning by using teacher feedback, without distillation, to instill thinking behaviors in language models.

Findings

Achieves 3.85% average improvement over zero-shot baselines.

Outperforms vanilla-GRPO on MATH-500, AIME, and GPQA-Diamond datasets.

Enhances reasoning capabilities without model distillation.

Abstract

Recent advances in test-time scaling have led to the emergence of thinking LLMs that exhibit self-reflective behaviors and multi-step reasoning. While RL drives this self-improvement paradigm, a recent study (Gandhi et al., 2025) shows that RL alone does not truly instill these new reasoning abilities - it merely draws out behaviors already present in the base models. This raises a question: How can we train the models that don't exhibit such thinking behavior to develop it in the first place? To this end, we propose ThinkTuning, a GRPO-based interactive training approach where we augment the rollouts of a student model with the guidance from a teacher model. A simple idea from classroom practice inspires our method: a teacher poses a problem, lets the student try an answer, then gives corrective feedback -- enough to point the mind in the right direction and then show the solution. Each piece of feedback reshapes the student's thoughts, leading them to arrive at the correct solution. Similarly, we find that this type of implicit supervision through feedback from a teacher model of the same size improves the reasoning capabilities of the student model. In particular, on average, our method shows a 3.85% improvement over zero-shot baselines across benchmarks, and on MATH-500, AIME and GPQA-Diamond it shows 2.08%, 2.23% and 3.99% improvements over the vanilla-GRPO baseline. Source code is available at https://github.com/3rdAT/ThinkTuning.