There's an interesting related study which was looking for causes of road rage, and found a correlation with the number of bumper stickers [1]. The content of the bumper stickers didn't matter, just whether or not there were bumper stickers. The conclusion was in how people interpreted the space of a car. More bumper stickers indicated that somebody viewed the car and the space that it occupied as personal space, rather than as transportation, or as a way to use a shared resource.

[1] https://www.nature.com/news/2008/080613/full/news.2008.889.h...