But he was intrigued by the fact that all immediate-return societies also spurned hierarchy, did not have chiefs, leaders, or institutional authority figures, and were intolerant of any meaningful material wealth differentials between individuals. He concluded that foragers’ attitudes to work were not purely a function of their confidence in the providence of their environment, but were also sustained by social norms and customs that ensured food and other material resources were evenly distributed. In other words, that no one was able to lord it over anyone else. And among them, one of the most important was “demand sharing.

Where foragers stoically accepted occasional hardships, farmers persuaded themselves that things could always be better if they worked a little harder. Farmers who put in the extra hours would, over time, usually do better than lazier ones who only ever made contingency for the one or two risks they considered to be the most likely. Thus among the Ju/’hoansi’s farming neighbors along the Kavango River the wealthiest ones were usually the most risk-averse—those who worked hardest to build good enclosures to protect their cattle and goats from predators at night; who spent long summer days diligently chasing birds, monkeys, and others drawn to their fields; who planted their seeds a little deeper; who went to the trouble of dragging bucketloads of water from the river to irrigate their crops just in case, as occasionally happened, the rains arrived late.

The fact that the Roman economy was sustained by what were, from the point of view of most citizens, intelligent working machines posed some similar economic challenges to those posed by large-scale automation. One of these was wealth inequality.

As powerful as the artisan collegia were, though, they were rarely able to do more than fight over the scraps falling from the tables of the wealthy patricians on whose patronage they depended. Rome’s eventual collapse was ultimately hastened by the corrosive inequality at its heart.

Thus, while those who are very wealthy like to believe that they are worthy of the financial rewards they have accrued, many poorer people don’t want to mess with the dream that they too might achieve such riches if only they work hard enough. For them to concede that perhaps the system was stacked against them—that money had become far better at begetting more money than working long hard shifts—would be tantamount to abandoning their sense of agency and their cherished beliefs that what made their countries different was that anyone who worked hard enough could be whatever they wished to be.