For years, social scientists have warned that mass shootings can be contagious: Intensive media coverage, particularly when a shooter's name and face become widely known, can serve as incentive to would-be copycats seeking the same notoriety. Likewise, the motivations for mass killing events can be contagious as well, particularly when perpetrators leave behind grandiose manifestos that inspire, or directly call on, others to follow suit.
That's doubly true of the massacre that took place last Saturday, when an 18-year-old white man from New York's Southern Tier traveled to Buffalo to target a supermarket in a predominantly Black neighborhood, killing 10 people and wounding three more. The shooting was only the latest in a series of mass killing attacks in recent years driven by the white nationalist "replacement theory," which holds that there is an orchestrated effort to replace white people in Europe, North America and elsewhere with nonwhite immigrants (or, for that matter, nonwhite citizens).
