Recent mass killings in Norway, America and in numerous countries have happened at locations as different as schools, movie theaters, and marathons. Though the actual number of mass killings has not changed in 30 years, they get a lot more attention now.

One trait they all share in common is psychiatric medication but unsurprisingly the biggest focus in a roundtable discussion among film studies scholars, psychiatrists and psychologists in a publication named Violence and Gender
is that they were all young males. The participants speculate about the possible reasons for high incidence of these crimes and the motives of the young male perpetrators.

Topics discussed include media bias when the criminal is a young male, the influence of the copycat phenomenon, whether these acts tend to be impulsive or deliberate and well-planned, triggers for these actions and whether revenge is involved, the impact of the current culture in schools in the U.S., and access to firearms.  The psychologist from Finland says that the American school system in America promotes social class, racial, and other differences among students more than the European school system - which is going to startle those who are non-elites in Europe and discover they have no way to start a business or get ahead in life if they were born to the wrong family and therefore did not go to the right school.

Forensic psychologist Reid Meloy cuts through the popular spin and reminds the panel that mass murder cases in the United States haven't changed since 1976. They are also not out of line with the rest of the developed world. They just get more attention because of the effort to ban guns in the US and the desire for Europeans to want to feel like their culture is superior. There are now approximately 20 of these cases per year among a population in excess of 300 million people who own a lot of guns. That means mass shootings are shockingly rare. Meloy does note that what should be examined is why mass murders have not gone down since 1976 - gun ownership is up in the US and still individual homicides are down. Even in California, an anti-gun culture, the curves in increased gun ownership and decreased gun murder are telling. What has changed since 1976 is the use of drugs for milder psychological conditions. 

Yuki Nishimura of Japan notes that guns are illegal there, so people strangle each other and that does not really lend itself to mass killing.

Citation: Mary Ellen O'Toole, Jorge Folino, James Garbarino, Steven M. Gorelick, Helinä Häkkänen-Nyholm, J. Reid Meloy, Stanton E. Samenow, Yuki S. Nishimura, 'Why Do Young Males Attack Schools? Seven Discipline Leaders Share Their Perspectives', Violence and Gender doi:10.1089/vio.2013.1505.