# Can fraternal twins be genetic?
**URL:** https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075
**Category:** Factual Questions
**Created:** [May 9, 2002, 1:59pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075 "2002-05-09T13:59:02Z")
**Posts on this page:** 12
**Page:** 1
### Author:  [@Kimberley](https://boards.straightdope.com/u/Kimberley)
#### Post date: [May 9, 2002, 1:59pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/1 "2002-05-09T13:59:02Z")
Hi there, just curious as to whether fraternal twins can run in the family, or if it’s usually just a fluke that someone has fraternal twins.
The reason I ask is that I am a fraternal twin and there are no other twins in either of my parents’ families that we know of, at least 4 generations back.
Someone on a different board that I post on says that it is genetic to have f.twins. Is this true?
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### Author:  [@Why\_A\_Duck](https://boards.straightdope.com/u/Why_A_Duck)
#### Post date: [May 9, 2002, 2:09pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/2 "2002-05-09T14:09:24Z")
Well, [this midwife](http://www.parentsplace.com/expert/midwife/qas/0,10338,166530_115622,00.html) mentions a lot of factors affecting the frequency of fraternal twins, including race and age, but doesn’t mention family history.
But [this link](http://www.parentsplace.com/pregnancy/labor/articles/0,10335,166527_111535,00.html) from the same site says that two-egg twinning passes down female-to-female through the generations.
So it sounds like that there could be a genetic factor, but that it is just as likely to have been a fluke.
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### Author:  [@Why\_A\_Duck](https://boards.straightdope.com/u/Why_A_Duck)
#### Post date: [May 9, 2002, 2:10pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/3 "2002-05-09T14:10:28Z")
PS: Welcome to the boards!
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### Author:  [@istara](https://boards.straightdope.com/u/istara)
#### Post date: [May 9, 2002, 2:18pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/4 "2002-05-09T14:18:37Z")
My mother has told me it is hereditary and skips a generation, meaning that as she’s a fraternal twin, I would be in line to have a pair myself. IF it’s true, and IF I have children, of course.
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### Author:  [@davidw](https://boards.straightdope.com/u/davidw)
#### Post date: [May 9, 2002, 2:35pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/5 "2002-05-09T14:35:59Z")
My wife was pregnant last year with twins before miscarrying, she’s a fraternal twin, and her father is a fraternal twin.
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### Author:  [@capybara](https://boards.straightdope.com/u/capybara)
#### Post date: [May 9, 2002, 2:54pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/6 "2002-05-09T14:54:50Z")
Likelihood of fraternal twinning is hereditary (although that doesn’t guarantee that a twin will twin-- it’s just an increased chance). Look up stats on the Yoruba, an ethnic group in Nigeria that culturally decided some time ago that to marry a twin was desirable, and now their fraternal twinning rates are very high. Apparently though, if my memory serves me, identical twinning is not hereditary.
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### Author:  [@CC](https://boards.straightdope.com/u/CC)
#### Post date: [May 9, 2002, 3:03pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/7 "2002-05-09T15:03:48Z")
just suggesting that “my mom” shouldn’t count as a cite here…
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### Author:  [@Kwyjibo](https://boards.straightdope.com/u/Kwyjibo)
#### Post date: [May 9, 2002, 4:39pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/8 "2002-05-09T16:39:25Z")
Welcome aboard Kimberley.
😉
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### Author:  [@istara](https://boards.straightdope.com/u/istara)
#### Post date: [May 9, 2002, 4:54pm UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/9 "2002-05-09T16:54:00Z")
> [@](#):
>
> \*Originally posted by CC \*
> \*\*just suggesting that “my mom” shouldn’t count as a cite here… \*\*
Probably not! But she’s interested in the twinning thing - being one - and has read up extensively on it over the years, so I respect what she’s told me on it as probably deriving from some medical article, rather than an Old Wive’s Tale.
Now my mother would really hate to be described as an Old Wife…
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### Author:  [@Chronos](https://boards.straightdope.com/u/Chronos)
#### Post date: [May 10, 2002, 5:47am UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/10 "2002-05-10T05:47:50Z")
> [@](#):
>
> My mother has told me it is hereditary and skips a generation, meaning that as she’s a fraternal twin, I would be in line to have a pair myself.
So far as I know, there’s no gene that follows a regular pattern of alternating generations. Usually, when folks refer to a gene as “skipping a generation”, they mean that it’s sporadic whether or not it’s expressed.
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### Author:  [@Cerowyn](https://boards.straightdope.com/u/Cerowyn)
#### Post date: [May 10, 2002, 6:09am UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/11 "2002-05-10T06:09:32Z")
As a father of twins, I was exposed to a lot of research on multiple births. The [Parents of Multiple Births Association](http://www.multiplebirthscanada.org/english/factsfigures.php) site gives this information:
> [@](#):
>
> Family history, mother’s age, number of previous pregnancies, and race are determining factors in the incidence of fraternal multiples.
And:
> [@](#):
>
> Fraternal twinning does not necessarily skip a generation.
The web site gives a lot of information, but most of their statistics are for Canada.
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### Author:  [@DPWhite](https://boards.straightdope.com/u/DPWhite)
#### Post date: [May 10, 2002, 6:35am UTC](https://boards.straightdope.com/t/can-fraternal-twins-be-genetic/108075/12 "2002-05-10T06:35:56Z")
I come from a family where there were in one generation three sets of twins (19th century or so). One non-twin sibling was father to identical twin boys, my second cousins. The previous generation sets of twins were all the same sex, and according to legend (none survived infancy) identical – but identical-ness could not at that time be confirmed.
Another family I know had identical twin girls. One of the girls gave birth to identical twin girls.