[jeremysmyth]

Not that much a joke actually.

According to University of Alabama criminologist Adam Lankford[1] the causes include fame:

    factors include a chronic and widespread gap between 
    Americans' expectations for themselves and their actual 
    achievement, Americans' adulation of fame, and the 
    extent of gun ownership in the United States.

[1] http://www.latimes.com/science/sciencenow/la-sci-sn-united-s...