Interesting point. The natural sex ratio at birth is estimated at 1.06, so that ratio of males to females for young Americans is not particularly out of expect

Interesting point. The natural sex ratio at birth is estimated at 1.06, so that ratio of males to females for young Americans is not particularly out of expectation. http://en.m.wikipedia.org/wiki/Human_sex_ratio http://en.m.wikipedia.org/wiki/Human_sex_ratio I couldn't readily find numbers, but I would speculate that there may also be more male than female immigrants at younger ages.