[stands2reason]

I am also a lefty and was breech! A very difficult childbirth. I wonder if birth trauma can cause lefthandedness.

[Tall_Texan]

My maternal grandmother was born in 1900 and developed into a lefty. Years later, when she was given an x-ray, it revealed she was born with a broken right collarbone. She said she did things lefthanded because it hurt less. Duh.