I’m a mirror twin and my brother and I are both right handed. Although to be honest my used to INSIST that I was born left handed and learned to use my right hand. I have doubts about this, but I don’t remember so I’ll take her word. Incidently I was part of a study because of my twinness. I’m sort of P’OD about it because I never figured out why.
I found an interesting article on the issue that seems to explain the misconception at http://www.twinstuff.com/mirrors.htm A researcher discovered that he could create twins by splitting an embryo which did, in some cases, produce asymetrical development. It was assumed that this was the process by which human twins were created and left/right handed pairs were assumed to be monozygotic even when they didn’t look the same.
The article suggests that handedness likely has nothing to do with mirroring. He notes that no one has ever found the normal asymetries of the brain to be reversed and 2/3 of left handed twins are the second born.
Some identical twins are opposite handed. These are called “mirror” twins. The fact is that most identical twins are identically handed, and, as right-hanedness is most common in humans, these twins are right-handed…
My two neices, Ariel and Nicole, are confirmed identical twins. Both are right-handed. One, however, is more adept at piano than the other…
a thought on the she “absorbed her twin” theory…
It does sometimes happen that a pregnancy that starts out as twins ends up with only one surviving child. For whatever reason, one of the fetuses doesn’t make it, and generally, it is absorbed by the mother’s body. There is also a syndrome (the name of which escapes me) in which one of the twins is much larger and healthier. Sometimes the smaller, weaker twin doesn’t survive. Perhaps this is what she had heard about?
Awful family story:
My mom’s older brother was, so it seems, originally meant to be a twin. When he was born, he was delivered along with the remains of his twin, who had died in utero and had not been fully absorbed by his mother’s body. Hearing this story as a young child, he assumed (for quite some time, it appears) that he had eaten his twin while in utero.