>Think about how you can recognize your friends without even seeing their face, by the way they walk, what they wear, how tall they are, and other contextual cl

>Think about how you can recognize your friends without even seeing their face, by the way they walk, what they wear, how tall they are, and other contextual clues. Yep, but think also how many times you approached a friend from behind and patted him/her on the back only to realize that you just patted a perfect stranger? I have no particular problem to believe that one's gait is "distinctive", but quite a few in believing that that particular stroll is "unique".