Wow, so not only are the findings from https://arxiv.org/abs/2506.21734 (posted on HN a while back) confirmed, they're generalizable? Intriguing. I wonder if this will pan out in practical use cases, it'd be transformative. Also would possibly instantly void the value of trillions of pending AI datacenter capex, which would be funny. (Though possibly not for very long.)
Hierarchical Reasoning Model
Guan Wang, Jin Li, Yuhao Sun
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Xing Chen, Changling Liu, Yue Wu, Meng Lu, Sen Song, Yasin Abbasi Yadkori
2025 · arXiv
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From the abstract
Reasoning, the process of devising and executing complex goal-oriented action sequences, remains a critical challenge in AI. Current large language models (LLMs) primarily employ Chain-of-Thought (CoT) techniques, which suffer from brittle task decomposition, extensive data requirements, and high latency. Inspired by the hierarchical and multi-timescale processing in the human brain, we propose the Hierarchical Reasoning Model (HRM), a novel recurrent architecture that attains significant computational depth while maintaining both training stability and efficiency. HRM executes sequential reasoning tasks in a single forward pass without explicit supervision of the intermediate process, through two interdependent recurrent modules: a high-level module responsible for slow, abstract planning, and a low-level module handling rapid, detailed computations. With only 27 million parameters, HRM achieves exceptional performance on complex reasoning tasks using only 1000 training samples. The model operates without pre-training or CoT data, yet achieves nearly perfect performance on challenging tasks including complex Sudoku puzzles and optimal path finding in large mazes. Furthermore, HRM outperforms much larger models with significantly longer context windows on the Abstraction and Reasoning Corpus (ARC), a key benchmark for measuring artificial general intelligence capabilities. These results underscore HRM's potential as a transformative advancement toward universal computation and general-purpose reasoning systems.
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There’s the hierarchical reasoning model https://arxiv.org/abs/2506.21734 but it’s very new and largely untested Though honestly I don’t think new neural network architectures are going to get us over this local maximum, I think the next steps forward involve something that’s 1. Non lossy 2. Readily interpretable
This paper I read from here has an interesting mathematical model for reasoning based on cognitive science. https://arxiv.org/abs/2506.21734 (there is also code here https://github.com/sapientinc/HRM) I think we will see dramatic performance increases on "reasoning" problems when this is worked into existing AI architectures.
Link to paper here https://arxiv.org/pdf/2506.21734 Still reading, but the benchmarks for ARC-AGI-1, ARC-AGI-2, Sudoku-Extreme (9x9), and Maze-Hard (30x30) look impressive.
sapientinc/HRM: Hierarchical Reasoning Model: https://github.com/sapientinc/HRM : > [...] Inspired by the hierarchical and multi-timescale processing in the human brain, we propose the Hierarchical Reasoning Model (HRM), a novel recurrent architecture that attains significant computational depth while maintaining both training stability and efficiency. HRM executes sequential reasoning tasks in a single forward pass without explicit supervision of the intermediate process, through two interdependent recurrent modules: a high-level module responsible for slow, abstract planning, and a low-level module handling rapid, detailed computations. With only 27 million parameters,…
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HRM achieves exceptional performance on complex reasoning tasks using only 1000 training samples. The model operates without pre-training or CoT data, yet achieves nearly perfect performance on challenging tasks including complex Sudoku puzzles and optimal path finding in large mazes. Furthermore, HRM outperforms much larger models with significantly longer context windows on the Abstraction and Reasoning Corpus (ARC), a key benchmark for measuring artificial general intelligence capabilities. These results underscore HRM’s potential as a transformative advancement toward universal computation and general-purpose reasoning systems. "Hierarchical Reasoning Model" (2025) https://arxiv.org/abs/2506.21734 .. https://news.ycombinator.com/item?id=44699452 (9 hrs ago)
Hi HN, We've seen LLMs struggle with complex, multi-step reasoning tasks. The common approach, Chain-of-Thought (CoT), often requires massive datasets, is brittle, and suffers from high latency. To tackle this, we developed the Hierarchical Reasoning Model (HRM), a novel recurrent architecture inspired by how the human brain processes information across different timescales (as seen in the diagram on the left). It's a small model that packs a huge punch. Here are the key highlights: Extremely Lightweight: Only 27 million parameters. Data Efficient: Trained with just 1000 samples for the complex tasks shown. No Pre-training Needed: It works from scratch without needing…
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massive pre-training or any CoT supervision data. Single Forward Pass: It solves the entire reasoning task in one go, making it incredibly fast and efficient. How It Works HRM consists of two interconnected recurrent modules that mimic brain-wave coupling: High-level Module: Operates slowly, like the brain's Theta waves (θ, 4-8Hz), to handle abstract planning and goal setting. Low-level Module: Operates quickly, like Gamma waves (γ, ~40Hz), to execute the fine-grained computational steps. These two modules work together, allowing the model to achieve significant computational depth while remaining stable and efficient to train. Astonishing Performance The results speak for themselves (see charts on the right). On tasks requiring complex, precise reasoning, HRM dramatically outperforms much larger models: Extreme Sudoku (9x9): HRM achieves 55.0% accuracy. Other models, including direct prediction and larger LLMs like Claude 3.7 8K, score 0.0%. Hard Maze (30x30): HRM finds the optimal path 74.5% of the time. Again, others score 0.0%. ARC-AGI Benchmark: On the Abstraction and Reasoning Corpus (ARC), a key test for AGI capabilities, HRM significantly outperforms larger models with much longer context windows. We believe HRM represents a transformative step towards more general and efficient reasoning systems. It shows that a carefully designed architecture can sometimes beat brute-force scale. We'd love to hear your thoughts on this approach! What other applications could you see for a model like this? Paper: https://arxiv.org/abs/2506.21734 Code: https://github.com/sapientinc/HRM
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