It was “customary” for cousins to marry in the Aegean Bronze Age, according to a team of archaeogeneticists studying ancient social customs. Cousin marriage is defined as the legal union of two people who share common grandparents. While this marriage practice was common in earlier times, it is still practiced in some societies today. “Worldwide, more than 10% of marriages are between first or second cousins,” claimed a 2009 New York Times article.
A research team from the Max Planck Institute for Evolutionary Anthropology (MPI-EVA) in Leipzig, Germany, has presented new archaeogenetic data offering “exciting insights” into the social order of Aegean Bronze Age Minoans and Mycenaeans. By analyzing 4,000-year-old genetic material from Bronze Age human bones the scientists have “for the first time” reconstructed a biological Mycenaean family tree . Furthermore, they discovered that it was “customary” to marry one’s first cousin.
Representational image of a genetic research lab. In this most recent study, archaeogeneticists have concluded that cousins married customarily in the Aegean Bronze age based on an analysis of ancient genomes. ( Gorodenkoff / Adobe Stock)
Celebrating Genetic First: Study Reveals Cousins Married in Aegean Bronze Age
The results of this new genetic study were published in the journal Nature Ecology & Evolution . In an article published on Eurekalert the new study’s lead author, archaeologist Philipp Stockhammer from the MPI-EVA, said with the help of the analysis of ancient genomes it has been possible “for the first time” to gain insights into kinship and marriage rules in Minoan Crete and Mycenaean Greece.
The researcher says recent methodological advances in the production and evaluation of ancient genetic datasets has made it possible for his team of geneticists to produce such extensive historic data. Stockhammer added that genetic data was even derived from regions where DNA preservation was hindered due to climate conditions, as it is in Greece.
Charting Lives, Marriages and Deaths in Ancient Greece
The new study focused on DNA gathered from human remains that were found in a 16th century BC Mycenaean settlement. And so loaded with quality ancient genes were the samples that the researchers were able to reconstruct the first gene- family tree ever using samples from the Mediterranean region.
Because some of the sons of the family were found buried in a tomb beneath a courtyard, it is suspected that they most probably still lived at home as adults. Furthermore, the sister of one of the son’s wives was also buried in the same family grave. What nobody on the research team expected to find, however, was clear genetic evidence that it was customary to marry one’s cousin some 4,000 years ago.
The well-known figure of a Minoan goddess, artistically appropriated and depicted holding DNA chains instead of snakes. The image represents a Mycenaean family tree in order to depict the frequency of cousin marriage. (Eva Skourtanioti / Nature)
Understanding Why Ancient Minoan and Mycenaean Cousins Married
The act of marrying one’s cousin wasn’t just secular to this one estate, but the team said around 4,000-years-ago cousin marriages were commonplace “across mainland Greece, on Crete and all the other Greek islands.” Eirini Skourtanioti, a study author who conducted the genetic analyses explained that while more than a thousand ancient genomes from different regions of the world have now been published, “such a strict system of kin marriage did not exist anywhere else in the ancient world.”
So why did so many cousins marry in the ancient Mediterranean world? While unsure of the reason, Stockhammer said that marrying one’s cousin perhaps “prevented the inherited farmland from being divided up more and more, by guaranteeing a certain continuity of a family in one place.” He explained that this is particularly important in the cultivation of olives and wine.
Olive harvesting in the Aegean Bronze Age. The new study posits that cousins married to protect their farmland. (Nikola Nevenov / Nature)
The Genetic Gamble to Save Profitable Estates
While the scientists did not mention this term, marrying one’s cousin to maintain an estate is known as “alliance theory” or “the general theory of exchanges.” The hypothesis of a “marriage-alliance” points towards the necessary interdependence of various families and lineages wherein marriage is a form of communication. And essentially, alliance theory attempts to understand inter-individual relations within society.
The reason opinions around the world vary so widely as to the merits of cousin marriage is because the children of parents who are cousins have a greatly increased risk of autosomal recessive genetic disorders . According to a 2012 study published in the Journal of Community Genetics , this risk is even higher in populations that are already highly ethnically similar, as they were in ancient Greece. So while ancient Greek cultures were marrying cousins to secure estates, every single one of those unions brought the family one step closer to genetic Armageddon.
Top image: Minoan Bronze Age family harvesting grain. The new study posits that cousins married to protect their family farmland. Source: Nikola Nevenov / Nature
By Ashley Cowie