4 September 2026

Apple research shows AI language models skip optimal logic

• Apple researchers tested large language models, the AI systems behind chatbots, on Bayesian logic, a method for updating beliefs based on new evidence.
• The models consistently failed to follow the mathematically optimal approach, instead using simpler shortcuts that deviate from correct logical reasoning.
• Surprisingly, these imperfect shortcuts often produced better results on real-world tasks than the theoretically perfect logical approach would have.

How it was covered

Deep Learning WeeklyEditorial team

Apple research finds LLMs deviate from optimal Bayesian updates when processing evidence, yet their non-Bayesian heuristic updates often outperform exact Bayesian approaches on downstream tasks.