Cute boy?

I always wondering why adults keep mistakenly recognized Maggie as a boy. But it is somewhat weird that every kid Maggie ran into can instantly recognized her as a girl. It seems that adults tend to judge things superficially. We tend to take face, hair, and dress into determining a kid's gender, which sometimes goes wrong. In the other way, kids just sense, probably, scent, motion, and interaction and determine whether he or she is.