Joseph Henrich

So groups can copy each other.

So we know that from the ethnographic record and historical cases, sometimes a group will say, oh, those guys have really good technology tools.

Maybe they'll get some migrants or something like that.

And then they can adopt the practices.

So that definitely happens.

But there's also plenty of evidence of violent conflict.

And the Reich Labs evidence and lots of other ancient DNA suggest that there are these dead end genetic lineages.

So, I mean, the Neanderthals are dead end in a sense, although we interbred with them.

So they're in us in some sense.

But they don't have their own pure lineage or anything like that.

The way I describe it in The Secret is that it's a package of things.

So another good example would be the Inuit expansion out of the north slope of Alaska.

And they expand all the way across the Arctic and eventually get to Greenland.

And they have a whole package of social practices, which helps keep them interconnected.

And then they have bows and arrows, which the group they're exterminating as they go along, the Dorset, doesn't have.

They have dogs and sleds.

They have along the coast, they have boats.

So they're doing whaling activities.

So there's a whole package that puts together that allows them to out-compete and eventually exterminate the Dorset.

And one of the things that happens, though, is the Dorset probably had better technology, but they expanded, they spread out, their languages diversified, they lost contact, and they began losing technology.