The Origin of Marriage (And the Evolution of Divorce)

A Dollars and Sex commenter wrote that the “origin of marriage was to create a legal contract by which a man could acquire a female slave.” Interesting point. Is there an economic story that explains the origin of this most-debated-of-all-institutions?

The first humans, those who lived between 5 and 1.8 million years ago, had very little use for marriage. Using the behavior of bonobos as the basis for how early humans would have behaved, it is presumed that early males and females had sex with many partners. Food sharing was principally in exchange for sexual favors, including sexual favors between same-gender pairs. Because females could collect food (fruits, nuts and insects) while still carrying and protecting their babies, males were not needed as protectors or providers. That meant that in this period neither partner gained from being in a committed pair.

As the climate warmed and the forests receded, humans began to move out into the savannah where their diet consisted of gathered vegetation, scavenged meat left behind by predators and, eventually, meat killed by hunters using tools. A more meat-based diet meant that babies were born earlier requiring more care from their mothers.

In this period (between 1.8 million and 23,000 years ago), the males and females whose offspring were the most likely to survive were those that formed the very first marriages.

These may not have been marriages in the way that we think of marriages today, but couples in this period would probably have stayed together for about three or four years before one, or the other, would wander off to start another family.

(Perhaps not coincidentally, this is exactly the length of time (3 or 4 years) at which divorce rates peak in modern day marriages.)

About 23,000 years ago, humans started to grow their own food, revolutionizing human relations. The invention of the plough over 4,000 years ago meant that the most productive household arrangements were ones in which men and women divided their tasks. Men were stronger and less physically tied to children and so they went out and worked on the land. Women stayed closer to the home and cared for children and engaged in a myriad of other chores.

This is the era in which marriage became the union between two people that was recognized by their community. Agriculture tied people to their land, meaning that at the end of the four-year period neither men nor women had any inclination to wander off to find a new family. And so they stayed together and worked as a unit to feed and care for the children they produced.

The creation of marriage as a legal contract between men and women came into being over time as communities settled on what was a “normal” way for them to organize a family and then codified that normalcy into law.

For example, if it was the norm within the group that men and women were responsible for feeding and caring for their own children. Then laws were created that gave men some assurance that the children they were raising were their own and women some assurance that their husband would not leave them all destitute.

So, the origin of marriage was not to create a legal contract that made it possible for men to acquire female slaves. I am not saying that men and women were never treated that way in marriage contracts, but the real origin of marriage came from the biological desire of both men and women to see their children survive – it was the evolutionarily dominate strategy.

Marriage is no longer needed for children to survive, so do we still need marriage?

Perhaps that is an issue we should address another day.