I was in Barnes & Noble the other day, coming slowly around a corner at the end of an isle, and I almost collided with another patron who was walking quickly to wherever they were headed. We would have run into one another, but I stopped moving and let them pass. They saw me when they came around the corner, but they didn't break their gait.

This happens all the time when I'm out in public, and it makes me wonder what would happen if I refused to stop moving, just the way they did. If I kept going, would they just wait until the last possible second to acknowledge that I wasn't going to stop, at which point they would stop themselves? Am I just the first person to quit in a game of chicken? The whole thing reminds me of the Prisoner's Dilemma; because of the context, we could call this particular problem the "Shopper's Dilemma".

What what actions earn me is adaptability. I was walking through the bookstore with a specific destination in mind, of getting from Point A to Point B. And I had the plan in my head, too. I had the route I was going to navigate through the bookstore mapped out in my head.

When someone got in my way, when I encountered an obstacle I didn't expect, I stopped and waited. Stopping right there, for that length of time, wasn't part of my grand plan, but I quickly incorporated it into the plan out of necessity.

People seem to be darting around with plans like this. The person who almost ran into me probably thought, "I'm done looking at Harry Potter books, now I'm going to go look at books filled with pictures of Cockatoos!" or something. And they started on their path. And my inadvertently getting in their way didn't sway them from their course. They were either unwilling, or, dare I say, unable to modify their plan.

I don't know what a social psychologist would say about this, but I'll bet this explains why some people are so prone to road rage.