A recent study has concluded that attractive couples are 26% more likely to have a girl as their first child as compared to less-attractive couples.  This conclusion was based on at-home interviews with over 2,900 randomly selected parents between the ages of 18 and 28.  As part of the interview the interviewer would rank the couple’s attractiveness from 1 (very unattractive) to 5 (smokin’ hot).

But why are attractive people more likely to have girls? Scientists studying humans and other species have found that parents who possess any heritable trait that increases male reproductive success at a greater rate than female reproductive success will have more males than female babies, and vice versa.  Because men value physical attractiveness more than women do when looking for a mate, good looks increase the reproductive success of daughters much more than that of sons. So attractive people should have more daughters, which is what the research confirmed.  This theory also suggests that, over time, women should have become more attractive than men. These data also confirmed this theory. More than half of all women in the sample — 52 percent — were rated as “attractive” or “very attractive,” compared with 42 percent of the men.

While this is interesting, realize that just because you personally had a boy or a girl as your first child doesn’t mean you are attractive or not attractive.  The sample size of you and your spouse is too small to come to any meaningful conclusion.

Source: http://www-personal.umich.edu/~choucc/Kanazawa.pdf