Paleogeneticists have applied their methods to 35 skeletons from the Hazleton North long cairn in Gloucester, England, which dates to around 3,700 BC. The reconstructed tree shows that 27 of these people were descended from one man and four women; the general assumption is that the women were the man's wives. The people of the next generation were all sons, which implies exogamy, with the daughters being married off elsewhere. In fact most of the people in the tomb were men, and all the relationships seem patrilineal. The descendants of two of the wives were all buried on the same side of the tomb, so I guess they formed sub-families of a sort.
This paints a very hierarchal and patriarchal picture of society in Neolithic Britain.