I think it has to do with the male mind, wanting to be able to see whats coming. . . Its an old hardwired part of hunters and the pack mind, and while i don't think that ALL men do this, i do think that a higher percent of "alpha males" prefer to, sit in the corner of a room (in order to see all in front, nothing behind), be the last to enter when a group goes into a space (similar reasons), and back into spaces. When asked about strange, seemingly mundane actions, I always revert to the fact that deep down, the human mind just wants to protect the body in which it is encased. We will naturally do ANYTHING, emotionally or physically, in order to stay safe.