# Did Left-Handed People 'Absorb' Their Right-Handed Twins? **URL:** \ **Category:** Factual Questions\ **Created:** [April 12, 2004, 2:57pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607 "2004-04-12T14:57:56Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [April 12, 2004, 2:57pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/1 "2004-04-12T14:57:56Z")
Is it true that most left-handed people were once part of a pair of mirror-image twins, and, while still in the womb, they somehow managed to absorb the proteins contained in their right-handed twin until there was nothing left of them? Thanks. ---
**Author:** ![Nametag](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/nametag/32/406_2.png) [@Nametag](https://boards.straightdope.com/u/Nametag)\ **Post date:** [April 12, 2004, 3:06pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/2 "2004-04-12T15:06:11Z")
Who the hell has been spreading that nonsense? Of course it’s not true. I can’t imagine how you would even prove that it isn’t true, because no one would bother collecting data disproving it. ---
**Author:** ![Olentzero](https://avatars.discourse-cdn.com/v4/letter/o/90ced4/32.png) [@Olentzero](https://boards.straightdope.com/u/Olentzero)\ **Post date:** [April 12, 2004, 3:06pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/3 "2004-04-12T15:06:45Z")
This is a new one. Where in the world did you hear that? ---
**Author:** ![JerH](https://avatars.discourse-cdn.com/v4/letter/j/bb73d2/32.png) [@JerH](https://boards.straightdope.com/u/JerH)\ **Post date:** [April 12, 2004, 3:07pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/4 "2004-04-12T15:07:52Z")
I’m curious where you heard this. While I’m not an expert on fetal development, I can’t imagine a connection between embryonic homicide and which hand you use to write with. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [April 12, 2004, 3:13pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/5 "2004-04-12T15:13:03Z")
Thanks. I read about this somewhere on the web a while ago, but I haven’t been able to find it. The author said that in many pregnancies ultrasound finds twins, but only one child is born. The surviving child in left-handed 50% of the time. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [April 12, 2004, 3:18pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/6 "2004-04-12T15:18:19Z")
Very sinister. ---
**Author:** ![Sofis](https://avatars.discourse-cdn.com/v4/letter/s/e5b9ba/32.png) [@Sofis](https://boards.straightdope.com/u/Sofis)\ **Post date:** [April 12, 2004, 4:19pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/7 "2004-04-12T16:19:06Z")
> [@Surreal](#): > > I read about this somewhere on the web a while ago, but I haven’t been able to find it. > > The author said that in many pregnancies ultrasound finds twins, but only one child is born. The surviving child in left-handed 50% of the time. If this is the case, wouldn’t identical twins have opposite handedness more often than one would expect from pure chance? (In fact, one might expect identical twins to have the same handeness, what with being identical - but that would depend one what it is that determines handedness, something of which I am completely ignorant.) Does anyone know if that is the case? ---
**Author:** ![Duckster](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/duckster/32/1244_2.png) [@Duckster](https://boards.straightdope.com/u/Duckster)\ **Post date:** [April 12, 2004, 4:19pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/8 "2004-04-12T16:19:24Z")
> [@Surreal](#): > > The surviving child in left-handed 50% of the time. So do babies born right-handed absorb their left-handed twin as well? ---
**Author:** ![Emilio\_Lizardo](https://avatars.discourse-cdn.com/v4/letter/e/898d66/32.png) [@Emilio\_Lizardo](https://boards.straightdope.com/u/Emilio_Lizardo)\ **Post date:** [April 12, 2004, 4:23pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/9 "2004-04-12T16:23:00Z")
I can’t find a cite right now but I recall that there is such a thing as a “merged twin” where two embryos combine to form a single individual. IIRC the phenomenon was discovered when a woman and her children were tested for organ-donor compatibility – the test showed that she was not related to her own children! As a merged twin she had eggs from both embryos, so the ones that got fertilized were actually from the other twin. A doc could give much more information. ---
**Author:** ![Diceman](https://avatars.discourse-cdn.com/v4/letter/d/22d042/32.png) [@Diceman](https://boards.straightdope.com/u/Diceman)\ **Post date:** [April 12, 2004, 4:23pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/10 "2004-04-12T16:23:08Z")
**Surreal:** The last I heard, the question of what causes handedness is still unresolved. ---
**Author:** ![Padeye](https://avatars.discourse-cdn.com/v4/letter/p/a9a28c/32.png) [@Padeye](https://boards.straightdope.com/u/Padeye)\ **Post date:** [April 12, 2004, 5:05pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/11 "2004-04-12T17:05:58Z")
**Emilio Lizardo** IIRC that kind of “merged” twin is called a chimera resulting in a peson with two different genetic profiles depending on where the sample is taken. ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [April 12, 2004, 5:08pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/12 "2004-04-12T17:08:55Z")
I still can’t find the page that talked about one twin absorbing the other twin’s nutrients, but I did find this [http://www.cascobayweekly.com/cbw2003/cover/cover01.22.04-4.stm](http://www.cascobayweekly.com/cbw2003/cover/cover01.22.04-4.stm) “_Anyone may have had an undetected twin in the womb. It is conjectured that since twins are more likely to be left-handed than the normal population, left-handed singletons may be surviving co-twins of a vanishing identical!_” ---
**Author:** ![asterion](https://avatars.discourse-cdn.com/v4/letter/a/4da419/32.png) [@asterion](https://boards.straightdope.com/u/asterion)\ **Post date:** [April 12, 2004, 5:09pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/13 "2004-04-12T17:09:56Z")
> [@Surreal](#): > > Very sinister. _groan_ ---
**Author:** ![Jurph](https://avatars.discourse-cdn.com/v4/letter/j/50afbb/32.png) [@Jurph](https://boards.straightdope.com/u/Jurph)\ **Post date:** [April 12, 2004, 5:42pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/14 "2004-04-12T17:42:37Z")
I think Pauli said it best when he said: “That’s not right. That’s not even **wrong**.” ---
**Author:** ![Bumbazine](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/bumbazine/32/362_2.png) [@Bumbazine](https://boards.straightdope.com/u/Bumbazine)\ **Post date:** [April 12, 2004, 8:36pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/15 "2004-04-12T20:36:18Z")
- Burp \* ---
**Author:** ![Flander](https://avatars.discourse-cdn.com/v4/letter/f/8c91f0/32.png) [@Flander](https://boards.straightdope.com/u/Flander)\ **Post date:** [April 12, 2004, 9:32pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/16 "2004-04-12T21:32:17Z")
> [@Emilio Lizardo](#): > > I can’t find a cite right now but I recall that there is such a thing as a “merged twin” where two embryos combine to form a single individual. I just had the most awesome image of a mini-biological Voltron! ---
**Author:** ![Mathochist](https://avatars.discourse-cdn.com/v4/letter/m/c89c15/32.png) [@Mathochist](https://boards.straightdope.com/u/Mathochist)\ **Post date:** [April 12, 2004, 10:29pm UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/17 "2004-04-12T22:29:53Z")
> [@Flander](#): > > I just had the most awesome image of a mini-biological Voltron! And I’ll form the head! ---
**Author:** ![Futile\_Gesture](https://avatars.discourse-cdn.com/v4/letter/f/f05b48/32.png) [@Futile\_Gesture](https://boards.straightdope.com/u/Futile_Gesture)\ **Post date:** [April 13, 2004, 12:06am UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/18 "2004-04-13T00:06:19Z")
Just another day in **Surreal** ’s never ending mission to seek out knowledge where no-one even suspected it existed. Also available in this series in GQ… Why Is Earwax So Bitter? Do Japanese Mothers Masturbate Their Sons To Put Them To Sleep? Why Do Mentally Retarded People Have ‘Bowl’ Haircuts? Do Aborigines ‘Fillet’ Their Penises? Where Did The Belief That Asian Women Are ‘Sideways’ Originate? Are A Lot Of Ladies’ Fashion Models Actually Men? What’s It Like Being A (Promiscuous) Professional Athlete? Are C-Section Babies’ Heads More Bulbous? Why Do People Drink Coke If They Prefer Pepsi? Starvation- Is Eating Your Own Poop Advisable? How Come You Never See Babies With Green Eyes? Could A 185# Man Sit On A Xerox Machine Without Breaking The Glass? If I Use The ‘B’ Word On The Internet, Will The FBI Tap My Phone? Does Eating Soy Products Make You Effeminate? Is Blood Pouring Out Of Your Gums When You Floss A Bad Sign? Do People In Sweden Really All Eat The Same Meal On Thursdays? My hat is off to you **Surreal**. I don’t know where you get it all from, but your General Questions are never boring. ---
**Author:** ![racinchikki](https://avatars.discourse-cdn.com/v4/letter/r/eada6e/32.png) [@racinchikki](https://boards.straightdope.com/u/racinchikki)\ **Post date:** [April 13, 2004, 12:19am UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/19 "2004-04-13T00:19:16Z")
> [@](#): > > … most left-handed people were once part of a pair of mirror-image twins… > [@](#): > > The author said that in many pregnancies ultrasound finds twins, but only one child is born. The surviving child in left-handed 50% of the time. The first statement does not logically follow from the second! This is putting aside all claims as to the truth of the second statement - you cannot take the second statement and logically derive the first from it. I can’t even figure out how to explain this clearly. SOMETIMES they find twins, but only one child is born. As a result of this particular type of pregnancy, HALF of the surviving children are left-handed. This doesn’t even mean that the surviving child “ate” the other one - it just means that, for whatever reason, the other wasn’t born. How does this possibly mean that MOST left-handed people (meaning MORE THAN HALF, and SIGNIFICANTLY more than half or it would just be “many”) not only WERE part of that particular type of pregnancy, but moreover “ate” the other child - something that wasn’t posited in the original statement? ---
**Author:** ![Dan\_Norder](https://avatars.discourse-cdn.com/v4/letter/d/4af34b/32.png) [@Dan\_Norder](https://boards.straightdope.com/u/Dan_Norder)\ **Post date:** [April 13, 2004, 12:37am UTC](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607/20 "2004-04-13T00:37:06Z")
> [@Emilio Lizardo](#): > > I can’t find a cite right now but I recall that there is such a thing as a “merged twin” where two embryos combine to form a single individual. IIRC the phenomenon was discovered when a woman and her children were tested for organ-donor compatibility – the test showed that she was not related to her own children! Sounds like you mean this case: “When two became one in the womb” [http://news.bbc.co.uk/2/hi/health/3264467.stm](http://news.bbc.co.uk/2/hi/health/3264467.stm) The “see also” links on that page have other interesting related articles. [Next page](https://boards.straightdope.com/t/did-left-handed-people-absorb-their-right-handed-twins/239607.md?page=2)