I worked for a Neurologist for a long time---when he noticed I was left-handed he told me my brain was backwards. When I laughed, he told me he was serious, that left-handers do have opposite brains sides for certain !!functions---
he said that that is why certain professions lean more left, like the arts and teachers and bosses---he seemed to hint that there was an intelligence difference but he never would come out and say if left-handers are supposed to be smarter---
I think he was afraid that if he said YES, I would ask for a raise!!! ha ha
Right handed, left thumb on top...good luck!