Earlier quoted context omitted.
in places with a lot more men than women both men and women converge on wanting a long term relationship, but in places with a lot more women than men There's also the narrative that places where men outnumber women, men become increasingly competitive and violent towards women and each other. An example is any blue collar "boom" town like North Dakota's fracking industry.
In china where men outnumber women due to family preference for a male heir, it has resulted in straight men having to compete with each other on an economic status basis to attract women, what happens in north Dakota is not a universal phenomenon.
Roughly stated the younger the population the more men you end up with. Generally this is balanced by woman having shorter 'breaks' between relationships until old age when women significantly out number men. See: 1950: http://en.wikipedia.org/wiki/Demographics_of_China#/media/Fi...
vs: 2010 http://en.wikipedia.org/wiki/Demographics_of_China#/media/Fi...
It's hard to read, but the gap actually looks smaller for 15 year olds now vs 1950.