arXiv:2605.27773: Study of 8 LLM models reveals that Chain-of-Thought reasoning is 96% decorative and does not affect model decisions
Research by Pruthvinath Jeripitya Venkata examined 200 questions across 8 language models and found that Chain-of-Thought reasoning (CoT) functions as a 'knowledge display layer' rather than a functional decision driver. Opposing answer pairs retain 96% CoT similarity, meaning explicit reasoning is not the cause of decision change. Only GPT-4o shows a statistically reliable link between reasoning and decision.