This is still very new research, but not implausible. See for example section 3.6 in this paper [1].
> By contrast, there are a lot of cultures (eg. India, the Arab/Muslim world) where marriage is societally more or less obligatory.
An interpretation of that could be that it’s a result of memetics [2], i.e. several successful cultures have invented marriage because it makes them successful. Marriage might significantly increase social stability at all scales. For an interesting discussion about these kind of arguments from cultural evolution, see this blog article [3].
[1] http://arxiv.org/pdf/1203.6231.pdf
[2] https://en.wikipedia.org/wiki/Memetics
[3] http://slatestarcodex.com/2015/07/07/the-argument-from-cultu...