He gave him a dollar ! <| sep |> Anthropological evidence is extremely unreliable as people have fudged things many times over . And looking at history from the perspective of a gene gives you mathematical models of behaviours that could evolve over time , and behaviours that would be selected against strongly . So when talking about an crosscultural institution , that is the right view point to take . There may be some environmental factors and perhaps some randomness , but you can not have institutions that arise that would not give some survival benefits to the practitioners of the behaviours . Ms . Coontz ' s argument seems to be some sort feminist theorising that marriage was a way to build alliances , and she seems to be completely making shit up , given that you can find heterosexual monogamous relationships in gibbons and some monkeys as well . There are critiques of her work that accuse her of ignoring evidence like this ahistorybystephaniecoontz . Having come across the disdain of activist historians towards truth to promote a narrative on many other occasions , I ' d not be surprised to see that this nonsense is also made up .