Let's define a new variable in the statistics of real life: Niceness. Your level of niceness is measured by how often you open doors for people, help old ladies cross the street, and change your pace when about to run into someone on the sidewalk.
While walking on campus, there are many people using the sidewalks at any time; it's busiest between classes. The many paths people take intersect wildly and people would normally run into each other if everyone just walked on their expected path at their expected pace. However, people with a high "niceness" measure will slow down or speed up as necessary to avoid these collisions.
Why do they do this? They could be really nice, not in a hurry, in a hurry, or socially inept and the mere thought of touching people is a fear too great to measure. For whatever reason, when two people are bound to collide with their current velocities, one person will change his/her pace to avoid the collision. This is determined by the person with the higher niceness level. When two people with low niceness are on a collision path, it is more like a game of chicken, and the loser will have to stop dead in his/her tracks to barely avoid the collision. These are fun to watch, and usually involve sorority girls talking on their cell phones. Probably to each other.
A problem with this system occurs when two people of similar, high niceness levels are on a collision path. Both people will change paces one way or another at very similar times and the collision will not be avoided until the miniscule difference is discovered in the previously mentioned game of chicken. This happened to me today. It's awkward, unavoidable, and usually only happens to people so obsessive-compulsive that they are forced to tell other people about it later.
Of course, this whole topic is void when in Minnesota, where everyone has equally high niceness levels. A collision will be encountered and velocity changes will be perfectly matched until they meet, stop, and argue about who should step first.
P1: "After you."
P2: "No, after you!"
P1: "I insist!"
P2: "
I insist!"
P3: "What are you guys talking aboot?"
P1&P2 (simultaneously): "This jerk won't step first"
P3: "Well, it seems that I've come into this predicament as well, but one of you two must go first."
P1: "It won't be me, I wasn't here first"
P2: "Neither was I"
P4: "What are you guys talking about?"
<this continues until the population of Minnesota is centered in one location and everyone freezes from the outside in, until the last one alive was clearly the first one there, passes, and seeks to repopulate the northern region.>