Do your identical twins write with the same hand?

[jollyma]

My friend has 4 year old twins born at 30 weeks. One prefers her right hand, the other prefers her left. Is this common or should she be looking in to why they have made these choices? She is slightly concerned as the 'left handed' twin has always been stronger all round but the little one is catching up.

My identical DDs are both LH.

I have a non-identical twin sister, I'm LH, she is RH.

Mirror twins are one LH one RH. They form when the fertilised egg splits late.

Carbon twins form when split happens earlier, and both will be the same handed.

Interestingly conjoined twins are when the split happens very late, on the border between viable and non-viable, when cell differentiation has just started to take place.