Dude, my daughter has done this from day one! Okay, week three, to be fair. My son smiles evenly, but my three-month-old has my grin that pulls to one side. So, I am not sure this is exclusive to Fi. I am not convinced that our patterns are that set so early on. However, we may be predisposed to favoring a certain pathway over another. Who knows the infant mind, anyway? Hell, maybe she does have Fi early on. I mean, anyone who has practiced EC (Elimination Communication) knows that babies communicate meaningfully and are therefore capable of a great deal more than people realize.