Been watching Sinnead O Connor sing in Danny Boy & Molly Malone. I have been focusing on the area of the lips/tongue/cheek on the left and trying to have my left lips/tongue/cheek initiate the movement. If I try to initiate the movement on my left side it is not the same as how I usually pronounce words. In fact I do not know how but it is interesting to watch my attempts. There is an almost reflective contraction in my musculature on the left as I watch her. (I watch with my right eye closed)
It again suggests to me the discrepancy of left and right is not completely innate but more learned behavior.