Here's one for you:
How many football players have more than one older brother?
http://cbs2.com/topstories/topstories_story_072091004.html
"While biologists look at hormones for answers about human sexuality, other scientists are looking for patterns in statistics. And hard as this is to believe, they have found something they call "the older brother effect."
"The more older brothers a man has, the greater that man's chance of being gay," says Bailey.
Asked if that's true, Bailey says, "That is absolutely true."
If this comes as a shock to you, you’re not alone. But it turns out, it’s one of the most solid findings in this field, demonstrated in study after study.
And the numbers are significant: for every older brother a man has, his chances of being gay increase by one third. Older sisters make no difference, and there's no corresponding effect for lesbians. A first-born son has about a 2 percent chance of being gay, and the numbers rise from there. The theory is it happens in the womb.
"Somehow, the mother's body is remembering how many boys she's carried before," says Breedlove. "The favorite hypothesis is that the mother may be making antibodies when she sees a boy the first time, and then affect subsequent boys when she carries them in utero."
"You mean, like she's carrying a foreign substance?" Stahl asked.
"And if you think about it, a woman who's carrying a son for the first time, she is carrying a foreign substance," Breedlove replied. "There are some proteins encoded on his Y chromosome that her body has never seen before and that her immune system would be expected to regard as 'invaders,'" he added."
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