Friday, February 8, 2008

Gender Trends

Some of my girlfriends and I were talking genetics the other day. As some of you know, genetics was one of my all-time favorite classes in college. I loved learning about the transmission of genes, the odds of passing on certain traits, how those traits combine to make what we "see", etc. It's all absolutely fascinating. Anyway, after our talks about genetics, I got to thinking about the make-up of our groups of friends.

In "real-life," Andy and I primarily hang out with 7 other couples. Between the 8 of us couples, there are 7 of us with a total of 17 children. Of those 17 children, there are 4 boys. Yup, only 4 and each of those boys are the only boy in their family. F1=3 girls, F2= 2 girls, F3= 1 girl, F4= 2girls, one boy, F5 & 6= 1 girl, 1 boy, F7= 3 girls, 1 boy.

Then I thought about my on-line group of friends. There are 9 of us in an exclusive group and we have a total of 25 kids. Of those 25, only 9 are girls. F1=3 girls, F2=3 boys, F3=4 boys, F4 & 5=2 boys, 1 girl, F6=2 boys, F7=2 girls, 1 boy, F8 & 9 both have 1 boy, 1 girl.

Now I remember from my genetics class that the odds and the probability of having children of all one sex are different. And I could dig up my old notes (yes, I still have them in the closet) but I really don't want to do that. So I found this link instead: It helps to explain the likelihood of having children of all the same sex. And it's funny, because even though the odds decrease (there's hope, Carol!) that after each child, they will all be the same sex, it seems that it happens more and more. I know of a family that has 3 children (2b, 1g) and they each went on to have 3 children, all same-gendered within each family. And of those 9 children, 3 have gone on to have children (3, 2, 2) and they are all same-gendered within their families, too. Hmmmmmmm...

Anyway, I was just thinking about this and wanted to put it out there. By the way, as many of you know, I come from a family with 2 girls and most of my cousins are all same-gendered as their siblings, too. Just a little food for thought on a Friday morning!

1 comment:

Mom to 3 Monkeys said...

COOL! That is so interesting. I love all that stuff too. I have to say that the traits is most fascinating to me. I always wonder what the chances of each trait passing on are, but I joke we'd have to have 12 kids to get a good look at all the odds and THAT'S NOT going to happen. Neat web site too. Looks like 50/50 when it comes down to it.