Your team is faster than ever. The question is for how long.
A 666-person study on what offloading the thinking quietly costs.
- The track
- Leads a team
- The rep
- About thirty seconds
- Published
- September 2, 2026
The Exhibit
AI made your team faster. That is real and not in dispute, so set it aside, because it was never the question. The question is what happens to a skill the team has stopped exercising. A 666-person study found a clean relationship: the more people offloaded their thinking to AI, the lower they scored on critical thinking. The study.
It is a survey, correlational, so it shows a pattern, not a cause. But the pattern is the one this newsletter is about: the work goes out faster while fewer people are doing the reasoning behind it. That gap, between what ships and what the team can still account for, has a name, and it is the thing every issue tracks. Faster today. The open question is for how long.
The study
Comprehension Debt
Comprehension debt: the gap between what gets shipped and what the team can still reason about.
Speed has a shelf life nobody is pricing. Your delivery is quick right now because the team is still fluent in skills it is quietly no longer practicing, and fluency you stop using fades. The risk was never that the team is slow. It is that the confidence you have in its craft today is borrowed against reps it has stopped doing, and you cannot see the balance running down on any dashboard you currently run. So do not only track how fast the team ships. Track whether it could still reason through the thing it just shipped.
The idea
The Rep
One for your next review:
In review, code that called an API once per item, one after another, gets changed to fire all the calls at once. Same results, much faster.
You are not grading the fix. You are listening for whether they reasoned about load at all. A strong answer names a failure mode unprompted: a rate limit, a connection pool, a downstream service falling over once the list is large. A weak answer says "it is faster" and stops. If the answer never reaches the failure mode, you are watching velocity, not comprehension.
(The phrase you want to hear is "bounded concurrency." If it comes up on its own, they reasoned about load, not just speed.)
About thirty seconds