Reason I do the nod, very simple, I want to acknowlege his presence but don’t want to spend any more energy on it then needed.
Well, my theory on the male nod phenemenon all goes back to laziness. The nod is a way of having an entire short conversation. Example:
Guy A walks down street, sees Guy B, both stop.
Guy A: Hello.
Guy B: Hi.
Guy A: How are you?
Guy B: Fine. You?
Guy A: Alright. Wife and kids?
Guy B: Fine, fine… How’s the job?
Guy A: Same old, same old. Well, I’ll see ya round.
Guy B: Yeah, see ya. Bye.
Guy A: Bye.
Or, Guy A sees Guy B, he nods, Guy B nods in return, eliminating all that dialogue.
Eventually we will evolve into a society of simple gestures, nothin’ but nods, shakes, and so forth. Each one slightly different than the rest, making it possible to have conversations in two seconds.
I do it, I don’t know why. I’m posessed. It’s, in a nutshell, recognition.