“You say you want a revolution?”

Well, it might not be far off.

That is according to a study published in Nature tracing characteristics of history’s most consequential revolutions.

Using a rubric called the Gini coefficient, scientists from Washington State University and 13 other institutions examined factors that foment economic inequality.

What they found has them worried.

According to the rubric, egalitarian societies receive a score of zero; societies with high inequality score a one.

As some gain economic advantage over others, civilization tends to drift closer toward inequality.

Coupled with researchers’ prior knowledge about how inequality leads to social instability, the study points to some disturbing trends in the United States today.

The study’s lead author, professor of archaeology and evolutionary anthropology,  Tim Kohler, Ph.D., said:

“We could be concerned in the United States, that if Ginis get too high, we could be inviting revolution, or we could be inviting state collapse. There’s only a few things that are going to decrease our Ginis dramatically.”

According to the 2016 Allianz Global Wealth Report, The United States’s current Gini score is .81, one of the highest in the world, as the cart below indicates.

Image credit: 2016 Allianz Global Report, https://www.inverse.com

But what is an appropriate indicator of wealth?

House size.

Using data from 63 archaeological digs, scientists examined societies’ composition from prehistoric times to modern.

Human societies began relatively equal.

Hunter-gatherer societies consistently earned Gini scores around .17.

The divide between rich and poor grew once humans started domesticating plants and animals, and switched to agriculture-based societies.

Learning to till land meant learning about land ownership; inevitably, some people wound up landless peasants.

Because these inchoate societies were no longer nomadic, it became easier for them to accumulate wealth, like land, and pass it down to future generations.

As farming societies grew, though, Gini scores rose.

This pattern continued until humans migrated to the Americas.

Researchers found over time Gini scores continued to increase in Old World Eurasia, receiving the highest historical Gini score of .59, but actually plateaued in the New World.

Researchers believe this plateau occurred because in the New World there were fewer draft animals, like horses and water buffalo, making it harder for new agricultural societies to accumulate and cultivate additional land.

But while that score is high, researchers note it is nowhere near as high as the scores they’re seeing now.

Researchers wrote:

“Even given the possibility that the Ginis constructed here may somewhat underestimate true household wealth disparities, it is safe to say that the degree of wealth inequality experienced by many households today is considerably higher than has been the norm over the last ten millennia.”

A global report from Credit Suisse shows today half the world’s wealth belongs to an ultra-rich one percent.

And the gap is growing.

Among inequality’s myriad effects on a society are social unrest, a decrease in health, increased violence, and decreased solidarity.

Dr. Kohler indicates humans have unfortunately never been good at peacefully mitigating these factors.

Historically, the only effective mitigation strategies have been plague, war, and/or revolution.

Hopefully history will not repeat itself in quite the same ways anytime soon.

Image credit: slideshare.net