Joseph Henrich

There's also the appearance of these voluntary associations, which are new kinds of monasteries.

And so the monasteries begin spreading throughout Europe.

But they're all linked in a network because, like, the Cistercians, they're all connected and they have big meetings.

So they're actually spreading a lot of knowledge around Europe as well.

So that's part of this kind of collective brain story.

So when you're thinking about China, the first thing to remember is that for a lot of the history, we can actually see that size difference mattering a lot.

So a lot of European invention or a lot of stuff used in Europe is flowing in, gunpowder, paper, printing press, stuff is flowing into Europe.

And so, okay, so then what happens after about 1,000 CE?

Well, the argument is that the destruction of the kinship group opens the floodgates to people moving around.

So a recent analysis that we've done is after a bishopric arrives at a 1.5 by 1.5 grid cell in Europe, people begin flowing in and out of that grid cell more.

And what we do to calculate that is we have a big database of a few million famous people and we have birth and death locations.

So we find out that the church arrives and suddenly people are free to move around.

So you have a flow of individuals around and you have rising urbanization.

So Europe passes China around 1,200 in the percentage of the population that lives in cities.

And cities are where a lot of the action is, cities and towns.

And you have the diversification of occupations.

So normally clans would specialize in different crafts, and you'd learn from your clan brothers and clan fathers how to do the occupation.

In Europe, you get guilds, and you get masters and apprenticeships developing where strangers will become an apprentice to a master, learn from him, move somewhere else as a journeyman, learn from that master, and then eventually set up a separate shop.

Lots of opportunities for a flow of ideas.

So it has to do with how the kinship system transformed the movement of people, the rising of urbanization, the nature of guilds, and then eventually you get universities and things like that.