I am, and have always been, a part of the right handed majority. But in the summer of 2003, I suffered an injury to my right hand that involved stitches on my dominant hand and a lingering reliance on my non-dominant side. I continue, despite the long-healed injury, to carry my change and wallet in my left pockets. I continue, seven years on, to carry my beer in my left hand.
In the course of ten days, I retrained my body. I find this fascinating…the idea that the body can be retrained so completely in such a short period of time because of a trauma is amazing. It may, or may not be related, but after this point, my left eye became dominant. My right eye had always been stronger up until this point.
In reality, this is not really that surprising; I found out a summer earlier that all the time I had been batting righty in baseball I should have been batting lefty. I am (or have become), it seems, mixed-handed.
The left brain is responsible for handedness. As are genetics. As is environment. And teaching.* And injury. Hand dominance, despite its biological predisposition, can be altered as needed. This is a pretty cool aspect of the human body, in my opinion. The adaptation is stellar.
I became mildly left handed due to a series of stitches in my dominant hand that made it difficult and/or painful to work with my dominant right hand, a result that has and likely will linger despite it being only 10 days of inconvenience. Other people become right handed because they are forced (less so now) by their teachers.**
Autobiographical note: Somewhere between 8-15% of the population are left handed, but about 2/3 of the men I have dated have been left handed.
*My grade 9 biology teacher was left handed until high school, at which time he was forced to become a righty. At some point in the interim, he reverted to his natural left handedness.