6 ideas
The mind is structured like a cathedral with a central nave of general intelligence surrounded by separate side chapels, each housing a specialized cognitive domain. Early human cognition kept these chapels sealed off from one another, so knowledge in one domain could not flow into another.
Human intelligence evolved as four largely independent modules: a technical intelligence for tool-making, a natural history intelligence for understanding the environment, a social intelligence for managing relationships, and a linguistic intelligence. Behavioral capabilities are predicted by which domains an organism possesses and whether they can communicate with each other.
The defining shift to modern human cognition was not adding new mental modules but breaking down the walls between existing ones, allowing knowledge to flow freely between technical, social, and natural-history intelligence. This integration—cognitive fluidity—is what suddenly produced art, religion, and complex tool design roughly 40,000 years ago.
Humans were anatomically modern for tens of thousands of years before showing modern behavior, proving that brain size and body form alone don't explain the cultural explosion. The bottleneck was the internal organization of the mind, not its raw biological hardware.
Artifacts in the archaeological record are read as direct evidence of the mental operations that produced them, so a tool's complexity and the mixing of domains it requires reveals how the maker's mind was organized. The unchanging simplicity of early hand axes across vast time signals isolated, non-communicating intelligences.
A 30,000-year-old ivory carving combining a human body with a lion's head could only be conceived by a mind merging its category for animals with its category for people. Such anthropomorphic art is taken as concrete proof that natural-history intelligence and social intelligence had finally fused.