The assumption has long been that throughout most of history the concentration of power and inequality both increase with population size, because people lacked the wherewithal to get things done without top-down, coercive leadership. These two studies [1, 2] showed that population size matters but is not deterministic. In both studies, it only explained around a quarter of the variability in equality or degree of autocracy.

In addition, in our data we see evidence for democratic practices in other parts of the world than ancient Greece and republican Rome at roughly the same time, or maybe even slightly earlier. These two civilizations may have had the biggest influence on modern society, which is a function of how records were kept and stored and transmitted over time, and we don’t mean to diminish the importance of those places. But they’re not unique as people have presumed. And it’s certainly not true that every place else was organized autocratically.

Finally, we show that everything did not change with farming. This is a very entrenched argument: the idea that with farming and sedentary life, everything changed rapidly, and that then we were on an inevitable course of increasing scale, increasing concentration of power, and so on. Our data don’t support that. It’s not that agriculture wasn’t a key innovation. It was, and it did have long-term impacts. But they weren’t always immediate or the same.

I think those are the key points: We are finding evidence that does not conform to very longstanding and entrenched views, not just in archaeology, but across the social sciences.