a study on the 'hallway' and social behavior

So, like a lot of work environments we have a bunch of hallways at our office. But there's this one particular hallway that is special. It's special because it's very wide (~15ft) and very long (~150ft).

The interesting thing about hallways, especially in office settings, you inevitably pass people.. and it's people you typically know but not very well,.. and a lot of times people you probably last saw within the past hour.

Here is where innate human behavior kicks in. We as a group have 3 different ways of acknowledging that person in the hall walking in the opposite direction about to pass you. This is emphasized by the giant hallway at my work where you can see the other person approaching from what seems like a mile away.

1) You ignore them completely. You either keep your eyes down.. or gaze past the person.. or if you're really not in any kind of social mood you look obviously away.

2) You give them the polite pursed-lipped head nod. I believe the pursed-lips are meant to be some sort of smile. (note: you don't have to actually be looking at the person to give this type of signal)

3) This is in my opinion the weirdest one: the look- right- at- the- other- person- then- widen- eyes- and- raised- eyebrows. What is this? A relic of our ancestors that is ingrained in our DNA? A way of saying 'I see you!' as if that was some sort of greeting? ... a warning perhaps from the time of cavemen? i dunno why.. but i do it too.

Of course if you feel really enthusiastic on a particular day many of us combine 2) and 3). And like a lot of social behavior if you remove this out of context you would look like some sort of crazy person that had skipped their last round of meds.

And as with all rules there are exceptions. Like just now, while finishing a very humorous conversation with a co-worker I began to genuinely laugh at what he just said. He turned the corner as I kept walked down our giant hallway with the biggest,.. dumbest,.. open-mouth grin that anyone could possibly have. And then there she was, out of nowhere, that young lady you really don't know at all coming the opposite way assuredly thinking 'that guy is waaay too happy.' Obviously i did the most natural thing,.. i toned down the laughing-face-with-no-sound down, diverted my eyes to the floor and picked number 1).