Models need tokens to think
A roughly fixed, small amount of compute happens per forward pass, so a model cannot do arbitrary work inside one token โ reasoning must be distributed across many tokens. andrej-karpathy's labeling demo: an answer-first solution ("The answer is $3. Here's whyโฆ") is training poison because it teaches single-token guessing; the step-by-step version spreads the arithmetic so no token carries too big a leap.
Explains a whole family of behaviors:
- Chain-of-thought works because it is the computation, not a presentation choice; RL-discovered reasoning (
emergent-reasoning-via-rl) bloats response length for exactly this reason. - Counting fails ("how many dots" crams everything into one token); spelling fails because models see tokens, not characters (strawberry's three Rs); both fixed by
use codeโ copy-pasting tokens into Python is easy, and the interpreter does the work. - 9.11 > 9.9 persists for murkier reasons (activations associated with Bible-verse markers) โ a reminder the Swiss cheese has holes theory doesn't predict.
The archive connection: this is why grilling-session-style workflows spend tokens on alignment and why feedback-loop-ceiling tools beat mental arithmetic โ same principle, practitioner form.
Source: report