We Europeans are well aware that among many developing nations, it is common to marry relatives. So the idea is, "the cousinier, the juicier."
What remains unclear, however, is whether this has been the original behavior of humanity or a later cultural development, despite some indications suggesting an increase in consanguineous marriages among humans in recent times.
To get an answer, one must of course examine human groups that lived long ago. And it was precisely such a research report that I recently came across.
The study I read analyzed the last hunter-gatherers inhabiting Western Europe, who soon became displaced by the farming newcomers spreading from the southeast of the continent - or merged with them. The examined individuals had inhabited southern Brittany in France approximately seven or eight thousand years ago.
The analysis of ten individuals from three different locations revealed that spouses were not sought from within their own groups but from among different groups residing in different locations. As a result, consanguineous marriages were avoided, despite the very small population of each group - and consequently, also of the hunter-gatherers living in the area.
Somewhat surprisingly, researchers also found that the hunter-gatherers did not seek spouses from farming communities, even though such communities existed in the vicinity. Thus, the hunter-gatherer communities of the time remained quite separate for a long time, even though there was migration from them to the farming communities.
Returning to the question of cousin marriages that initiated this blogpost, based on the study I've discussed, it can be concluded that the original inhabitants of Europe did not practice such marriages.
In other words, they had an excellent understanding that marrying cousins was not sensible. This seems to be not clear to all contemporary human groups, those who, for one reason or another, have adopted consanguineous reproduction in their culture.
Previous thoughts on the same topic:
Violent demographic changes in Denmark
History of Finland I: How did Finland become culturally part of the West?
Long distance trade
