Odds of b/g versus b/b, g/g

Hello Everyone,

I feel as though I haven't been on TS for months. I have been having many problems logging on!

Anyway, I read this article on the internet that discussed the odds of twin gender. I am sorry for not having a proper citation, but I found it after I googled twins. Here is what it says, "On the other hand, two-thirds of dizygotic, or fraternal, twins will be either girl/girl or boy/boy sets."

What does everyone think about that? Does anyone have any hard evidence to prove or dispute this article? I have noticed a lot of the Moms on here have b/g sets.

 

QUOTE(trouble squared @ Aug 20 2007, 05:24 PM) [snapback]373007[/snapback]
Hello Everyone,

I feel as though I haven't been on TS for months. I have been having many problems logging on!

Anyway, I read this article on the internet that discussed the odds of twin gender. I am sorry for not having a proper citation, but I found it after I googled twins. Here is what it says, "On the other hand, two-thirds of dizygotic, or fraternal, twins will be either girl/girl or boy/boy sets."

What does everyone think about that? Does anyone have any hard evidence to prove or dispute this article? I have noticed a lot of the Moms on here have b/g sets.


Interesting...I would be curious to see if anyone else had come across any articles. I had not read anything like that, especially since we are expecting b/g twins.

 

Statistically, your possible outcomes would be:

A = Boy, B = Boy
A = Girl, B = Girl
A = Boy, B = Girl
A= Girl, B = Boy

Four outcomes, with two of them being b/g combos, would give you a 25% of b/b, a 25% chance of g/g and a 50% chance of b/g. I think that the article is wrong.

 

http://multiples.about.com/od/pregnancy/a/genderselect.htm

That is the link to the "article" that says the first posters quote. For what it's worth, they are only talking fraternal twins and do not include identical.

 

The one thing my doctor said was that 2 in 3 are fraternal, but never gave odds of sexes.. BUT we are having 2 boys.

 

QUOTE(jasonsmommy @ Aug 20 2007, 02:46 PM) [snapback]373031[/snapback]
The one thing my doctor said was that 2 in 3 are fraternal, but never gave odds of sexes.. BUT we are having 2 boys.


hello,
i saw on one of the forums u said u were expecting 2 boys? how early did you find that out? and are they id?

 

QUOTE(SommerNyte @ Aug 20 2007, 04:36 PM) [snapback]373018[/snapback]
Statistically, your possible outcomes would be:

A = Boy, B = Boy
A = Girl, B = Girl
A = Boy, B = Girl
A= Girl, B = Boy

Four outcomes, with two of them being b/g combos, would give you a 25% of b/b, a 25% chance of g/g and a 50% chance of b/g. I think that the article is wrong.


Ditto this. The author of the article is incorrect in their assumption that there are only three possible outcomes. And yes, they are speaking only of fraternal twins.

 

I understand statistics. I was wondering if the article was correct and the gender odds are not a straight up math formula. Perhaps there is some other genetic explanation. Sorry this is confusing- I hope this makes sense.

 

Nope, the article is just wrong. The 50/25/25 ratio is in my twins books as well. Now with identicals, it skews a bit in favor of g/g over b/b but they didn't give exact numbers.

 

I wonder if they are using this formula:

A: Boy B: boy
A: boy B: Boy
A: Girl B: girl
A: girl B: Girl
A: Boy B: Girl
A: Girl B: Boy

It doesn't make much sense stastically, as you could go on and on with the variations, but it gets the 2/3 to 1/3 ratio, just a thought?

 

QUOTE(trouble squared @ Aug 21 2007, 01:49 PM) [snapback]373526[/snapback]
I understand statistics. I was wondering if the article was correct and the gender odds are not a straight up math formula.
Maybe this has something to do with it -- http://www.sciam.com/askexpert_question.cf...3&topicID=3 -- but then it seems that a g/g set would have the lowest odd, still not in line with what the article says...

 

QUOTE(xavier2001 @ Aug 21 2007, 09:29 AM) [snapback]373569[/snapback]
I wonder if they are using this formula:

A: Boy B: boy
A: boy B: Boy
A: Girl B: girl
A: girl B: Girl
A: Boy B: Girl
A: Girl B: Boy

It doesn't make much sense stastically, as you could go on and on with the variations, but it gets the 2/3 to 1/3 ratio, just a thought?



In the multiples class I took, we were told that for fraternals 1/3 are g/g, 1/3 are b/b and 1/3 are b/g. Maybe they are using this logic?