It all sounds a bit sinister to me . No ! But seriously ; I wonder if it has anything to do with vision ? I do some things left handed , like dealing cards ,or shooting (bolt-action rifles were always a problem as I had to change hands to work the bolt on my service-issue SMLE .303 ,and sub-machine guns were out,otherwise I got a faceful of empties !) and I mount a bicycle the "wrong" way .I believe this to be due to having a "lazy eye" (my right one) on which I had several operations as a child , resulting in a very dominant left eye. My father was perfectly normal ,although he used a knife and fork left-handedly.
Personally , I'd give my right arm to be ambidextrous .