Our sister site Atlantic Cities has a great post on the way people avoid socializing on long-haul bus trips, inspired by research done by a Yale graduate student named Esther Kim who undertook arguably the most grueling doctoral thesis in the world: Riding Greyhound for two years. So your dissertation had you trekking to the wilds of Papua New Guinea to measure bat guano for weeks at a time? At least you got to travel to exotic places and camp in the jungle. As AC's Eric Jaffe tells it, Kim, a sociologist, chose to spend 2009 through 2011 doing something so boring, familiar, and tedious that many of us would rather walk. But she found what she was looking for: People acting like jerks to avoid having to deal with other people. Kim calls it social disengagement, and if you've ever taken a long-haul bus trip, the behavior will sound familiar, per Jaffe:

Once passengers acquired a seat they began their performance to dissuade potential row partners. They avoided eye contact, stretched their legs to cover the open space, placed a bag on the empty seat, sat on the aisle and blast earphones, pretended to sleep, looked at the window blankly. They also contorted their expressions into the "don't bother me" face or the "hate stare," writes Kim, borrowing the latter phrase from Goffman. When sharing a row was inevitable, riders sometimes inched over and made more room for someone who seemed to fit the "normal" mold.

The entire post on Kim's research is worth a read in full at Atlantic Cities.