Definition
The Cognitive Revolution is the cluster of changes, beginning around 70,000 years ago, that gave Homo sapiens a qualitatively new kind of mind. Most concretely it is a transformation of language — from a system for referring to immediate, observable things to one that can talk about absent objects, abstract categories, hypothetical futures, and entities that do not exist at all.
Harari does not claim to know the genetic or neurological trigger. What he claims is the consequence: with this new linguistic capacity, Sapiens could share fictions — stories about gods, ancestors, tribes, and rules — and coordinate the behavior of large groups of strangers around those stories. No other animal can.
Why it matters
How it works
The Cognitive Revolution is best read as an upgrade to a single skill — flexible reference — with cascading downstream effects. Once language could refer to absent and nonexistent things, it could be used to gossip about individuals not present, to plan hunts that have not yet happened, to bind together people who have never met, and to enforce rules that no individual invented.
Each of these capabilities scales group cooperation differently. Gossip scales sociality to the ~150-person limit of personal acquaintance. Shared fiction breaks that limit. With strangers cooperating around a common imagined order — a tribe, a god, a king, a state — Sapiens could organize armies, build cities, run trade networks, and outcompete every other large animal on Earth.