Shipping code with AI assistance is fast, but a new study suggests it might be costing you critical understanding. A January 2026 experiment by Anthropic researchers found that junior developers using AI assistance scored an average of 50% on coding assessments, while those working without AI assistance scored 67%. The study, which focused on learning the Python library Trio, indicates that while AI helps you finish tasks, it may not help you internalize the logic required to maintain them.

The Illusion of Competence

The core issue isn't that AI produces broken code; it's that it produces convincing code that you didn't write. When a requirement changesβ€”such as adding persistence to a product filterβ€”developers who relied heavily on AI often struggle to reason about where state lives or how to modify the architecture. The study observed that participants who used AI to delegate work entirely showed weaker understanding than those who used it to ask conceptual questions or verify their own predictions.

Practical Habits for Builders

You don't need to ditch Copilot to fix this gap. The author recommends a three-step loop: explain the flow in your own words before touching the code, make a small manual change to test your mental model, and investigate failures by predicting outcomes before asking AI to fix them. Instead of prompting "Fix this," try asking AI to "Identify two plausible causes and suggest how I can distinguish between them." This shifts the AI from a code generator to a debugging partner.

Key Takeaways

  • Anthropic's January 2026 study found a 17-point assessment gap between AI-assisted and non-assisted junior devs.
  • AI assistance did not significantly reduce completion time in the study, challenging the efficiency argument for simple learning tasks.
  • Conceptual questions and self-verification yield better skill retention than blind delegation of implementation details.
  • Teams must protect time for review and failure investigation, not just feature delivery, to prevent skill atrophy.

The Bottom Line

If you can't explain why the code works, you don't own it. Use AI to speed up the boring parts, but force yourself to predict the outcome before you run the code.

Reference

Shen, J. H., and Tamkin, A. How AI Impacts Skill Formation.