" Since virtually all human societies organized themselves tribally at one point, many people are tempted to believe that this is somehow a natural state of affairs or biologically driven. It is not obvious, however, why you should want to cooperate with a cousin four times removed rather than a familiar nonrelative just because you share one sixty-fourth of your genes with your cousin. No animal species behaves in this manner, nor do human beings in band-level societies. The reason that this form of social organization took hold across human societies was due to religious belief, that is, the worship of dead ancestors. Worship of dead ancestors begins in band-level societies; within each small group there may be shamans or religious specialists whose job it is to communicate with those ancestors. With the development of lineages, however, religion becomes more complex and institutionalized, which in turn affects other institutions like leadership and property. It is belief in the power of dead ancestors over the living and not some mysterious biological instinct that causes tribal societies to cohere. One of the most famous descriptions of ancestor worship was provided by the nineteenth-century French historian Numa Denis Fustel de Coulanges. His book The Ancient City, first published in 1864, came as a revelation to generations of Europeans brought up to associate Greek and Roman religion with the Olympian gods. Fustel de Coulanges pointed to a much older religious tradition that was shared by other Indo-European groups including "
― Francis Fukuyama , The Origins of Political Order: From Prehuman Times to the French Revolution