Despite what many may think, handedness is not a choice. It can be predicted even before birth based on the fetus’ position in the womb. So, if handedness is inborn, does that mean it’s genetic?
Well, yes and no. Identical twins, who have the same genes, can have different dominant hands. In fact, this happens as often as it does with any other sibling pair.
From the TED-Ed Lesson Why are some people left-handed? – Daniel M. Abrams
Animation by TED-Ed