Learning Adaptive Parallel Reasoning with Language Models
Authors: name: Jiayi Pan, name: Xiuyu Li, name: Long Lian, name: Charlie Snell, name: Yifei Zhou, name: Adam Yala, name: Trevor Darrell, name: Kurt Keutzer, name: Alane Suhr

Scaling inference-time computation has substantially improved the reasoning
capabilities of language models. However, existing methods have significant
limitations: serialized chain-of-thought approaches generate overly long
outputs, leading to increased latency and exhausted context windows, while
parallel methods such as self-consistency suffer from insufficient
coordination, resulting in redundant computations and limited performance
gains. To address these shortcomings, we propose Adaptive Parallel Reasoning
(APR), a novel reasoning framework that enables language models to orchestrate
both serialized and parallel computations end-to-end. APR generalizes existing
reasoning methods by enabling adaptive multi-threaded inference using spawn()
and join() operations. A key innovation is our end-to-end reinforcement
learning strategy, optimizing both parent and child inference threads to
enhance task success rate without requiring predefined reasoning structures.
Experiments on the Countdown reasoning task demonstrate significant benefits of
APR: (1) higher performance within the same context window (83.4% vs. 60.0% at
4k context); (2) superior scalability with increased computation (80.1% vs.
66.6% at 20k total tokens); (3) improved accuracy at equivalent latency (75.2%
vs. 57.3% at approximately 5,000ms). APR represents a step towards enabling
language models to autonomously optimize their reasoning processes through
adaptive allocation of computation.