A new study has revealed a correlation between
the number of bumper stickers on a car and the aggressiveness of the driver's behaviour, presumably as bumper stickers indicate a territorial mindset on the part of the driver. Interestingly enough, there was no correlation between the content of the bumper stickers and the driver's behaviour, so a "Visualise World Peace" sticker would be as much of a danger sign as a "Don't Mess With Texas" one.