While researching his new book, A Farewell to Alms, Gregory Clark wondered if the descendants of English people who survived disasters like the Black Death gained, through natural selection, a greater resistance to disease. This greater immunity, he supposed, might help explain how the Industrial Revolution came about.
In support of the disease-resistance idea, cities like London were so filthy and disease ridden that a third of their populations died off every generation, and the losses were restored by immigrants from the countryside. That suggested to Dr. Clark that the surviving population of England might be the descendants of peasants.As the wealthy dropped in social status, says Clark, they passed down (culturally, or perhaps genetically) their capitalist values to the workforce that drove the Industrial Revolution.
A way to test the idea, he realized, was through analysis of ancient wills, which might reveal a connection between wealth and the number of progeny. The wills did that, but in quite the opposite direction to what he had expected.
Generation after generation, the rich had more surviving children than the poor, his research showed. That meant there must have been constant downward social mobility as the poor failed to reproduce themselves and the progeny of the rich took over their occupations. “The modern population of the English is largely descended from the economic upper classes of the Middle Ages,” he concluded. [Link]
Most of my ancestors sat out the Industrial Revolution, and, in light of my life of abject poverty, I'm guessing I lack the capitalism gene. I'm well suited for serfdom.