Eli5:what’s the cause of someone being right or left handed? And why the vast majority is right handed?

Question

Eli5:what’s the cause of someone being right or left handed? And why the vast majority is right handed?

In: Biology

Answer 1

I was born right handed and when growing was doing everything with my right hand.

When I was like 3 or 4 I broke a couple fingers on my right had and had to wear a cast that restricted my whole hand. I started doing stuff with my left hand and when the cast came off I never went back to using my right hand. Even to this day, almost 40 years later, I can’t hold a pencil or throw accurately with my right hand.

It makes me think it is a co boating of mental is physical development.