Admittedly, this is going to be unscientific. But what poll on here claims to be otherwise?
I’m looking for parents with three (or more) kids, the first two kids being the same sex. This can be your parents’ kids, your kids, your relatives, your friends. Just think of the first real example that comes to your mind.
So you have the first two kids of one particular sex…
Here are a few examples from my family
My Parent’s: 3 Boys
My case: Two boys One girl
My Brother: Three Boys
My Youngets Brother: One boy
My Father’s side four Boys two Girls (3 Boys 1 Girl, 1 Girl, 1 Boy)
My Uncle (Father’s side) three Girls
My Aunt (father’s side) two Boys one Girl
My Mother’s side: Two boys three Girls (Boys were the oldest)
My Aunt (mother’s side) Two Girls One boy
My Uncle (Mother’s side) Two boys one girl
Basically, what I’ve heard is that if you have two kids of the same sex, the third kid will be of that same sex a disproportionate amount of time. Far greater than 50%.
Four examples in my family, where there at least three children and the first two were the same gender:
FFF
MMM - F
FFM
MMM - MFMMMFM
The third child’s sex is independent from the sex of the first two. The way you’ve phrased the question, it should be the same or different sex 50%/50%.
I answered for my sister-in-law’s kids (male, different) but then thought of me and my brothers (male, same) and my wife’s family (female, same).
No, because it’s not entirely a coin toss. There are biological factors involved such as exposure to estrogen/testosterone. I think.
My Mom: she’s got two older sisters, so FFF
My sister: she had two girls, then had a third, so FFF
My friend: she had three boys, then a girl, so MMMF
Some examples from my family…
Uncle Everett and Aunt Sally:
Two girls and then a boy.
Grandma Regina and Grandpa Chuck:
Two boys and then a girl
Grandma Alice and Grandpa Vito:
Two girls and then another girl
Uncle Sal and Aunt Lana:
Two boys and then another boy
So 50-50
I started a similar thread a while ago (locked as it was zombified) and you can use some of the stats from there as well if you want…
Third in our family was a girl after two boys.
G
The answer was based on my father and his siblings, but it would apply to many of his relatives as well. Curiously enough, my mother’s side of the family tends to get “female - same as the other two.”
I know an extraordinary number of families of four kids where the first 3 are the same and the fourth different.
Then there’s my sister who has five kids - two sets of twins M; M/F; M/M.
When it comes to data like this, I’d think that “extraordinary” would be at least 500 families.
I’m the middle of three boys. My mother is the middle of three girls. My wife is the middle of three girls. My father-in-law has a younger brother who also has three girls (those two have an older sister who managed to produce male offspring).
My parents had 3 girls before finally getting it right with me! 
(Actually, I was a rhythm baby who drove my RC mom to the sin of birth control!) :eek:
Mine went boy, boy, girl, boy.
My father and mother
Daughter
Daughter
Son
His brother and wife
Daughter
Daughter
Daughter
Daughter
My next door neighbors
Daughter
Daughter
Daughter
Daughter
The neighbors on the other side
Son
Son
Daughter
My best friend’s family
Son
Son
Daughter
I have other friends whose families had all daughters or all sons. I don’t sense a pattern.
My sister:
B, B, G
Everyone else in the family has only 2.
Off the top of my head I know of four three-kid families. One is my mom and her siblings, the other three friends and their siblings.
They go like this:
girl-girl-boy
boy-boy-boy (I know for a fact that boy #3 was a last attempt for a girl)
boy-boy-girl
boy-boy-girl
I was the third boy of three, myself; so I voted for “Male same as the first two.” However, my kids are B G B, and then there seems to be another boy on the way. (Wasn’t my fault!)
X, X, Y is the sequence of my brats (now grown up).
My parents had only girls.