Interesting study about how we became what we are:
In September 506 C.E., the fathers of what would later become the Roman Catholic Church gathered in southern France to draw up dozens of new laws. Some forbade clergy from visiting unrelated women. Others forbade Christians from marrying anyone more closely related than their third cousin. The authors of a sweeping new study say that last, seemingly trivial prohibition may have given birth to Western civilization as we know it.“If the authors are right, or even in the vicinity of being right, it couldn’t be bigger,” says Stephen Stich, a philosopher and cognitive scientist at Rutgers University in New Brunswick, New Jersey, who wasn’t involved in the work. “What they are offering to explain is the emergence of democratic institutions, of individualism in the West.”
This in not a new theory — iirc Jonathan Haidt discussed it years ago, as well as Steven Pinker — though they glossed over the importance of church policy.
Also it’s a good example of how odd history can be.