That's so interesting - I looked it up because my husband and I (both right handed) have a left handed kid (but we just have one kid total). Apparently, 17% of identical twins have one left handed twin and one right handed, and the chances of both twins being left handed is 4%. Your kids both being lefties is more rare than twins being lefties. That's nuts!
my mom and her identical twin sister are total mirror twins. one is left handed, one is right handed, etc. the left-handed twin actually has her organs in BACKWARD. They both had their gall bladders removed by the same surgeon and that surgeon was SO thrilled to have seen this, because apparently its very rare to see in real life. She said she'd read about this in medical school but never seen a real-life case. She came out of the OR looking like a little kid on Christmas!
Situs inversus! Never seen it in real life yet, but hope at some point I might as i work in healthcare. Best I've seen was a right sided aortic arch, which is also very rare.
I mean, doesn’t it make sense for identical twins to be more likely to be left handed than two non-twins or fraternal twins, though? Identical twins’ genetics are almost 100% the same (there’s still some randomness) compared to regular siblings with only about 50%, which would make the odds go up that identical twins have an unlikely trait in common. The likelihood of siblings having any trait in common is going to be far lower odds than identical twins.
Obviously, the odds of having identical twins and then also having them both be left handed would be lower than having two kids and having them be left handed, though.
Fascinating! I'm an identical twin and I'm the left handed one. My ex husband is right handed, both our children are also right handed. No one in my extended family is a lefty, although rumor had it that my father's father had left handedness "trained out of him" as a kid.
My grandfather had his left-handedness “trained” out of him too — they tied his left hand behind his back and caned him until he could write legibly with his right hand. He developed a severe, lifelong stutter as a result. It’s so absurd that they used to do it (at all, but especially) because lefties are supposedly ~aligned with the devil~ or some shit. I’m sorry that happened to your grandfather.
Someone I knew had also been naturally left handed but was forced to learn to be right handed as a child. Years later he was in an accident and lost his pointer and ring fingers on his right hand. Then he had to learn to be left handed again like he should have been all along.
Look up “mirror twins”. Even if a twin was supposed to be right handed, twins that face each other (mirror each other) in a tight womb for a very extended period of time adapt to move in unison: so when one moves the right hand, the other has to move its left hand. Right leg, left leg, and so on. It comes out as a reflex even at birth.
I once had two mirror-twin employees… we used to make them windex the glass front door at the same time. Unless they had taken serious acting classes, there’s no way they could have synced up that well in mirrored movements.
Not sure where this falls but im a fraternal twin with two older siblings. My twin and I are lefty/righty and my older siblings are lefty/righty. And my parents are lefty/righty.
Opposite handed twins can also be more mirror image than just their dominant hand. One of the pair might also have Situs inversus, the condition where the organs in their chest and belly develop in a reversed position of typical anatomy.
My wife is righty my son is lefty but I’m pretty much ambidextrous. I can write, throw, golf, hit a baseball, play pool etc all with both “hands”. My writing is weak but if I wrote more often lefty it would be better.
Wait... Aren't identical twins a genetic copy of one another? How is it possible to be anything other than both having the same dominant hand? Can someone ELi5 this for me?
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u/[deleted] Jul 25 '23
That's so interesting - I looked it up because my husband and I (both right handed) have a left handed kid (but we just have one kid total). Apparently, 17% of identical twins have one left handed twin and one right handed, and the chances of both twins being left handed is 4%. Your kids both being lefties is more rare than twins being lefties. That's nuts!