Apple’s LLM study draws an important distinction about reasoning models

🗓️ 2025-06-10 05:29

There’s a new Apple research paper making the rounds, and if you’ve seen the reactions, you’d think it just toppled the entire LLM industry. That is far from true, although it might be the best attempt to bring to the mainstream a discussion that the ML community has been having for ages. Here is why this paper matters.

The paper in question, The Illusion of Thinking: Understanding the Strengths and Limitations of Reasoning Models via the Lens of Problem Complexity, is certainly interesting. It systematically probes so-called Large Reasoning Models (LRMs) like Claude 3.7 and DeepSeek-R1 using controlled puzzles (Tower of Hanoi, Blocks World, etc.), instead of standard math benchmarks that often suffer from data contamination.

The results? LRMs do better than their LLM cousins at medium complexity tasks, but collapse just as hard on more complex ones. And worse, as tasks get harder, these “reasoning” models start thinking less, not more, even when they still have token budget left to spare.

But while this paper is making headlines as if it just exposed some deep secret, I’d argue: none of this is new. It’s just clearer now, and easier for the wider public to understand. That, in fact, is great news.

The headline takeaway is that models marketed for “reasoning” still fail on problems a patient child can master. In the Tower of Hanoi, for example, models like Claude and o3-mini fall apart after seven or eight disks. And even when given the exact solution algorithm and asked to simply follow it, performance doesn’t improve.

In other words, they aren’t reasoning, but rather iteratively extending LLM inference patterns in more elaborate ways. That distinction matters, and it’s the real value of the Apple paper. The authors are pushing back on loaded terms like “reasoning” and “thinking,” which suggest symbolic inference and planning when what’s actually happening is just a layered pattern extension: the model runs multiple inference passes until it lands on something that sounds plausible.

This is not exactly a revelation. Meta’s AI Chief Yann LeCun has long claimed that today’s LLMs are less smart than house cats, and has been vocal that AGI won’t come from Transformers. Subbarao Kambhampati has published for years about how “chains of thought” don’t correspond to how these models actually compute. And Gary Marcus, well, his long-held “deep learning is hitting a wall” thesis gets another feather in its cap.

The study’s most damning data point might be this: when complexity goes up, models literally stop trying. They reduce their own internal “thinking” as challenges scale, despite having plenty of compute budget left. This isn’t just a technical failure, but rather a conceptual one.

What Apple’s paper helps clarify is that many LLMs aren’t failing because they “haven’t trained enough” or “just need more data.” They’re failing because they fundamentally lack a way to represent and execute step-by-step algorithmic logic. And that’s not something chain-of-thought prompting or reinforcement fine-tuning can brute-force away.

To quote the paper itself: “LRMs fail to use explicit algorithms and reason inconsistently across puzzles.” Even when handed a solution blueprint, they stumble.

Yes. Just not new news.

These results don’t come as a big surprise to anyone deeply embedded in the ML research community. But the buzz they’ve generated highlights something more interesting: the wider public might finally be ready to grapple with distinctions the ML world has been making for years, particularly around what models like these can and can’t do.

This distinction is important. When people call these systems “thinking,” we start treating them as if they can replace things they’re currently incapable of doing. That’s when the hallucinations and logic failures go from interesting quirks to dangerous blind spots.

This is why Apple’s contribution matters. Not because it “exposed” LLMs, but because it helps draw clearer lines around what they are and what they’re not. And that clarity is long overdue.

Upgrade: A previous version of this text stated that Yann LeCun had compared current LLMs to house cats. In fact, his claim is that today’s LLMs are less capable than house cats. The text has been revised to better reflect his position.

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Marcus Mendes is a Brazilian tech podcaster and journalist who has been closely following Apple since the mid-2000s.

He began covering Apple news in Brazilian media in 2012 and later broadened his focus to the wider tech industry, hosting a daily podcast for seven years.

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