Boys run in the Family

**Warning: While I attempt to avoid vulgarity on my blog, I am one to speak frankly. While I do not go into details about “how babies are made”, this post contains mention of sperm and x and y chromosomes. If this is something you are uncomfortable with, please accept my apologies and feel free to not read further.**

Davene is 36 weeks pregnant with her fourth. After three boys, they’ve decided to not find out this baby’s sex in advance. Debate has been raging as to whether this baby is going to be a girl or a boy. Many of Davene’s blog readers think this one’s going to be a girl. To which Davene replies, “Do they realize what the odds are?”

I mentioned this to my sister, a newly minted Physician Assistant, and she said, “50-50”. Because the odds for a baby’s gender are just like the odds for tossing a penny and having it land heads up. Every time you toss a penny, the odds are 50-50 as to which side it’ll end up on, regardless of what’s gone on before. This is statistical fact.

I can think of plenty of couples who have thought their hopes were gone for a child of a certain sex–but who ended up with one nonetheless. One aunt and uncle had four girls–and were surprised when their fifth (a true surprise baby) turned out to be a boy. I’ve seen even more cases where the fourth was of the opposite sex than the three going on before. Another aunt and uncle, my former pastor’s family, Davene’s neighbor Wilma, to name just a few.

But that doesn’t stop me from thinking, in a radically unscientific way, that a certain sex does “run in the family.”

Take for instance, my dad’s family (4 boys, 1 girl). Three of the boys have children. One has 6 boys and 1 girl. One has 3 boys. My dad has 4 boys and 3 girls.

Then there’s my mom’s family (10 girls, 2 boys). Both of the boys have children. One has 4 girls and 1 boy. The other has 2 girls and 1 boy.

Notice that I’m only mentioning the boys. That’s because ultimately it’s the man that determines whether a baby’s a girl or a boy. Women have xx chromosomes, Men have xy chromosomes. Mom always contributes an x to baby, Dad contributes an x to make a girl baby or a y to make a boy baby. That’s why I haven’t mentioned the girls on my Mom’s side of the family.

But even those tend to support my theory that a certain sex “runs in the family”. My mom married into a family of boys–and has 4 boys and 3 girls. My aunt Rachel married into a family of boys and has 4 boys and 2 girls. My aunt Janet married into a family of boys and has 2 boys and a girl.

So I tend to think that maybe a certain sex does “run in a family”. I’ve thought that for quite a while. It’s just today, though, that I thought of something to take my unscientific theory to even higher scientific heights: “I wonder why a certain sex might ‘run in a family’. Is it because a certain family tends to have more x or y containing sperm–or is it because the x or y sperm in a particularly family have a competitive advantage?

Wow. Talk about stretching out pseudo-science. (Although, if you happen to know any real science concerning whether certain sexes “run in families”, please let me know so I can apply some real science to my hunch.)

**Note on the use of the word “sex”: I realize that by using the word “sex” rather than the more socially acceptable “gender”, I may have inadvertantly caused offense or caused this page to lose its family-friendly rating. However, according to Merriam-Webster, sex means “either of the two major forms of individuals that occur in many species and that are distinguished respectively as female or male especially on the basis of their reproductive organs and structures.” Gender, on the other hand, means “the behavioral, cultural, or psychological traits typically associated with one sex.” Thus, sex is a biological term and gender is a cultural term. When I speak of a baby’s sex, I am referring to the child’s biological category, not to his or her cultural identification with a particular sex.**