Some of the self-subsisting communities are unusually remote and shun outside influence.Over the decades some of the communities have become so isolated they suffer a thinning gene pool.In today's society, more than half of all marriages fail for various reasons.The fact is that relationships, whether dating or married, are hard.
Interesting, and given that the Hutterites are well known for their expertise in breeding farm animals--and for the number of serious birth defects (Bowen-Hutterite syndrome, neural tube defects) that appear in their populations, one can see where the UL might come from. To quote a geneticist who's been studying the Hutterites for many years: In many ways, Hutterites are the perfect study group for "natural" mate choice among humans.
Their social networks typically remain within the colony, although they do communicate with other nearby colonies and also with a few links in the public sector, since they are primarily agricultural communities and sell their products in order to provide for the needs of the colony.
Babies and children, and their respective nuclear families, stay close throughout their lives, although once the children reach about 3 years old they begin the process of integration into the colony, which consists of strict rules, learning hard work and ones place within the colony, and correction and guidance from the colony as a whole, rather than from just their parents.
This has led to expulsion or persecution in the several lands in which they have lived.
In Moravia, the Hutterites flourished for over a century, until renewed persecution caused by the Austrian takeover of the Czech lands forced them once again to migrate, first to Transylvania, and, then, in the early 18th century, to Ukraine, in the Russian Empire.