Sifting through the pages of the CIA factbook, I noticed the virtual universality of higher infant mortality rates at the international level for boys than for girls. There are two marginal exceptions, Nepal and the Northern Mariana Islands, the latter also having the most unbalanced gender ratio favoring women in the world (numerically anyway--the red-blooded men of the islands might argue it actually favors them). For the other 221 countries or territorities for which there are data, boys are more likely than girls to die in the first year of life.
I wonder how various feminist theories explain this. Boys are expected to be tougher and consequently receive rougher treatment from their parents even before they begin crawling? They are encouraged to be more aggressive, and adopting a martial outlook leads them to engage in more risky behavior? How about blank slatist belief systems that hold environment up as the determinative factor in everything? Similar stories, I suppose.
One reason for this disparity is that boys tend to be larger than girls are and consequently are relatively more difficult to deliver without complication. Male babies are apparently also more susceptible to premature birth and respiratory problems than girls are. Further, though I am only speculating here, it seems plausible that as males tend to show more diversity than females do in several attributes like intelligence, they are more likely to suffer from too many bad draws that, in totality, lead to poor health outcomes.