Much time and money seems to be spent by worthy scientists, isolated from reality in their laboratories, discovering things most of us already know. Well, here's one of my own, and it took no time at all, and I won't be charging for it. Are you ready? Ok. Here goes.
The reason most men wear their hair parted on the left is because most women are right-handed. And when these men were small, their right-handed mothers stood in front of them with the hairbrush in their right hands. Equipped thus, it was easier to brush the hair from left to right, leaving the parting on the left. Have you got that?