Notice that there are many more males than females in the USA for in the age bracket when relationships form. The ratio is 1.07 (.73/.68 = 1.07) for 19 year olds. It's incredibly high and I wonder why that is?<p>Think about the implication: No matter what those 107 guys do there will be only enough girlfriends/wives/lovers for 100 hundred of them. The ratio reverses only after age 45.<p>This might explain the extraordinary effort by men to meet women in the U.S. as compared to some other countries and earlier times in U.S. history. The dating sites, the PUA courses, and even Zuckerberg's original motive for Facebook. The competition is super intense because it's a zero sum game. For 7% of men it's futile. (I'm simplifying by ignoring 19 year olds with 45 year old girlfriends, gays relationships, and many other factors.)<p>Most people know that women outnumber men <i>overall</i>, but are unaware that the statistics for young people are reversed.