Why are mass shootings becoming more common (since the 80s)? [View all]

[HiPointDem]

The news on Friday was horrific...Yet these sorts of headlines are also becoming gut-wrenchingly familiar. Of the 12 deadliest shootings in U.S. history, six have taken place since 2007...Mass killings appear to be on the upswing — even as other types of homicides and violent crimes are becoming less frequent...

For much of the 20th century there were, on average, a handful of mass killings per decade. But that number spiked in 1980, and kept rising thereafter. In the United States, there have now been at least 62 mass shootings in the past three decades, with 24 in the last seven years alone. This has happened even as the nation’s overall violent crime and homicide rates have been dropping.

One theory is that mass murders (usually defined as murders with four or more victims over a short time period) are somehow contagious. Back in 1999, four public health researchers published a famous study titled “Media and Mass Homicides...” They...found that different incidents appeared to be influenced by each other in a number of ways, often spanning many years and across continents...

Mental illness is one likely factor — a survey by Mother Jones found that at least 38 of the 61 mass shooters in the past three decades “displayed signs of mental health problems prior to the killings.” Yet the studies above note that researchers still have a ways to go before they understand the exact connection between the two.

And what about the availability of guns as a factor? Researchers have found a connection between guns and homicide — more guns tend to lead to more murder. And guns will obviously make any mass attack far deadlier. Note that there was also an attack on 22 students in a Chinese elementary school on Friday. But there was a key difference: The man only had a knife, and there were zero fatalities.

Note: This is a bit misleading: Since 2010 in china 21 people have been killed & 90 wounded at schools by 'rampage killers' armed with knives, cleavers, or similar weapons:

http://en.wikipedia.or/wiki/School_attacks_in_China_%282010%E2%80%932011%29

Again, though, overall gun violence in the United States has been declining in recent years while mass shootings and killings appear to have become more commonplace. It’s not entirely clear why that is. And it’s an increasingly important question.

http://www.washingtonpost.com/blogs/wonkblog/wp/2012/12/14/why-are-mass-shootings-becoming-more-frequent/


I did my own analysis of the motivation for the mass shootings since the 80s listed in an article at Mother Jones.

http://www.motherjones.com/politics/2012/07/mass-shootings-map

I threw out one case because it was about a family dispute and killed only family members, and apparently missed one along the way, leaving a total of 60. Of those:

- 30% were over workplace disputes.
- 30% had no known motivation, either because public information was limited or information available showed no clear motive.
- 23% could be classified as motivated by revenge, with targets loosely related to the parties the shooter deemed responsible for his problems (e.g. school personnel where the student failed to achieve an academic goal).
-8.3% were related to some kind of romantic/spousal dispute or disappointment.
- 5% were attacks on some general group the shooter deemed to be a problem (e.g. sikhs)
- 3.3% were outliers: one was a felon killing police and one labeled 'terrorism' on the military (though this isn't completely clear -- it was the case of Nidal Hasan).

In some of these cases the shooter was deemed 'crazy,' but I just looked at what the shooter himself said/wrote where that was available, and if that didn't exist or there was not enough information I classified it as unknown.

It seems that the majority of mass shootings are motivated by revenge for some perceived wrong or existential threat, most often economic or status related, or a combination of the two (e.g. as in failing to win some academic goal).

So if I were to try to answer the question of why mass shootings have become more common, that's where i'd start. It seems a reasonable hypothesis, since these cases started to increase in the 80s and have apparently increased of late.

I also think that the recent spate of knife rampages in China, despite the pooh-poohing by the columnist above, may have similar motivations.

Talking exclusively about availability of guns & mental health services seems to me to be an easy out.