I am one of three siblings; my mother has three siblings, and my father has three siblings. My spouce and I have actually two girls. Nearly all of my first cousins are female—in reality, it’s a long-running laugh that ladies take over both edges of my children and therefore if you’re a male in my own household (sorry, dad and bro! ) you’ve got the persistence of saints!

I’ve heard for years—and my own OBGYN swore to me—that when considering to gender in utero, it is the male that determines whether infant exists feminine or male. Okay, fine. The quickest “sperm” determines gender. First got it.

But why when we meet a household with only daughters (such as for instance my mother along with her three siblings; no brothers) or a family members that’s chock-full of only sons, we wonder: is sex in utero really and truly just 50/50, or do a little females around really provide delivery to just boys or just girls? Continue reading →