thinking has two speeds — and tools operate in only one
SYSTEM 1
fast
automatic · instinctive · effortless
pattern recognition
syntax recall
familiar debugging
SYSTEM 2
slow
deliberate · effortful · constructive
system design
trade-off reasoning
synthesis · judgment
agents
S2 tasks, S1 engagement
WHAT THE DATA SHOWS
39 points
gap between perceived and actual productivity
METR, 2025 · experienced developers · RCT
83%
couldn't recall passages they'd just written with AI
Kosmyna et al., MIT Media Lab, 2025
Kahneman, Thinking Fast and Slow, 2011
every tool before AI automated S1 tasks.
AI is the first tool that operates in S2 territory.
the interface determines which one you get.