Why Are Killing Rampages Increasing? A Guest Post


Peter Turchin is a professor of ecology and mathematics at the University of Connecticut and author of War and Peace and War: The Life Cycles of Imperial Nations. Much of his work concerns a new field known as cliodynamics, which attempts to discover general principles that explain the functioning and dynamics of historical societies. He has agreed to be a guest blogger this week; this is his first of two posts.

Why Are Killing Rampages Increasing?

By Peter Turchin

A Guest Post

So far in 2008, The New York Times reported at least six shooting rampages. Just two weeks ago a man shot or stabbed 10 people in northwest Washington, six of whom died. After his arrest, he told the police that God told him what to do and told him to “kill evil.”

Are these episodes of senseless mass murder increasing? A systematic search of The New York Times from 1946 to the present suggests that the increase is real and very dramatic:

MassacreNumber per year, plotted by decade.

Over the last half-century the incidence of massacres — shooting rampages, killing sprees, etc. — increased roughly 10-fold. These numbers exclude crime-related (along the lines of Reservoir Dogs) and family-related (“Man Shoots Wife, Kids, Self”) multiple murders.

Why is this happening? Note that I am not concerned here with why killing rampages occur, but why they are on an increase.

The rise in massacres began during the 1960’s and shows no signs of abating. It’s a long-term trend, and I think it is telling us something about fundamental ways in which our society is changing.

I am interested in this trend because my research, in general, focuses on investigating long-term dynamics of historical societies (I call this cliodynamics, Clio being the muse of history). One empirical result from this program is that societies tend to experience recurrent waves of violence and political instability; these waves are themselves the results of long-term social and economic trends (more on this in my book War and Peace and War). In other words, when we want to explain trends evolving on a slow time scale, we look to mechanisms operating on the same scale.

A study by The New York Times in 2000 found that the majority of massacres happen in two situations: at the workplace (about one-third of the total) and at school (one-fifth). Here’s my hypothesis for the increase of work-related rampages (I will deal with school rampages in my next blog):

We know that during the 1970’s something changed in the American economy, and in a very fundamental way. Between 1930 and late 1970’s, real wages grew essentially monotonically (overall, they grew by a factor of 3.5). Since then the wage stagnated (white-collar workers) or even declined (blue-collar workers). These are official statistics (Bureau of Labor Statistics); the actual situation must be worse, because the real rate of inflation is probably underestimated by creative folk at government statistical agencies.

In any case, the costs of big items that define the middle-class way of life — houses, college education, medical insurance — have increased faster than the official inflation rate.

The implications are obvious, and it is surprising that they are rarely brought up in the context of massacres. As their economic prospects deteriorate, many breadwinners find themselves under unendurable pressure to maintain the socially expected level of consumption. Under these conditions, people — whose psychological problems would be borderline in the gentler economic climate of the 1950’s — today “go postal.” So the harsher the economic conditions, the greater the numbers of those whose latent psychological problems develop into full-blown psychosis.

The New York Times from 2000 provides some indirect support for this hypothesis: 57 percent of rampage killers in their database were unemployed when they went on rampage. Remember the 1993 movie Falling Down? The resemblance between the fictional character, brilliantly played by Michael Douglas, and real rampage killers, described in the press reports that I read, is uncanny.

To close, I submit that there is a plausible connection between worsening economic conditions (for most Americans, except the rich) and an increase in workplace rampages. Substantial and growing proportions of massacres, however, occur at schools and universities. I will address this issue in my next blog.


Reading these selected quotes from the school-shooting phenomenom, one must seriously consider the 'mind-control' theory of motive:


Michael Carneal, Paducah, KY, Heath H.S., 3 dead, 5 wounded

--"Carneal told one psychiatrist that he felt like he was in a dream..." "It was like I was in a dream, and I woke up."


Andrew Wurst 14, Edinborough, PA, Parker Middle School(at off-campus school dance); 1 dead, 3 wounded

--"...Andrew had mentioned in a letter to a friend that 'the voices are coming again.' " "Andrew thinks he is real, but everyone else is unreal. Other people are programmed to act and say what the government, mad scientists, or a psycho wants them to say." [interesting juxtaposition of those last three groups!]

--Andrew told his girlfriend "We are all in reality in hospital beds being monitored and programmed by these mad scientists, and this world is not real for them. The scientists watch over us to see what we're doing." [uh oh, he wasn't supposed to remember this part!]


Kip Kinkel, Springfield, OR, Thurston High School, 1 dead, 7 seriously wounded

When Kip was asked, "Where do you think the voices came from?" Kip replied, "Well, I had some theories. Maybe it was from the devil... the government might have put a chip in my head. Government satellites might have transmitted to the chip.... At first I thought the voices were outside of my head because they were so very loud, like surround sound." Kip also claimed he believed one satellite gave voices to the microchip and another followed his every movement.


Columbine 15 dead, 22 wounded

A fellow student(Dustin Harrison) had Eric Harris in his psychology class: "He just basicially said that he was having [u]trouble[/u] with this [u]recurring dream[/u]--that he woke up one morning and came into the school, and he just started shooting students and teachers as they came by, and then he said it always ended up....ended with him just blowing the school up.


T.J. Solomon, 15, Conyers, GA, Heritage High, 6 wounded--Witnesses described the shooter as initially "calm, sedate, vacant, and robotic."

-- T.J. had suicidal thoughts and believed to hear voices giving him commands. “He heard voices telling him to do strange things, but they were robotic voices, not human voices”


Charles 'Andy' Williams, Santana HS, San Diego County (2 dead, 13 wounded)

--"I don't think 'crazy' is the right word," Williams said. "It's like an out-of-body experience when I was in my body I was out of my body at the same time."

"So you didn't feel you were there? What do you mean?" he was asked.

"I didn't feel like it was actually me doing it," Williams said.

"Is this really me? It was like hearing and seeing things, but not me pulling the trigger."

Another detective characterized the boy as "vacant" during questioning.


Rafael S., aka "Junior," 15, Islas Malvinas Middle School No. 2, Carmen de Patagones, Argentina, 3 dead, 5 wounded

--Police said they arrested Rafael without resistance soon afterwards in the schoolyard. He was in a state of shock, witnesses said, and could not speak a word.

--He said he wasn't conscious at the time he shot, and he was sorry....

--When a judge interviewed him afterwards he said only "I'm sorry, it happened very fast, and I did not decide anything."


Jason Clinard, 14, Stewart County High School, Cumberland City, TN

He shot his school bus driver six times, killing her as she stopped to pick him up.

--the teen told staff at Middle Tennessee Mental Health Institute that he had been "hearing voices for about five years, which instructed Jason to harm others and himself"

--The boy told the psychiatrist, "it's like somebody else controlling my body."

----He said that the last thing he remembered was watching television that morning. ... Jason said that the next thing he remembered was after the alleged offense. He said he was heading into the woods when his mother called him on his cell phone... at that time he "woke up" in the woods..." He said he was surprised to learn he had shot somebody.


Jeff Weise, Red Lake HS, 10 dead, 4 wounded

Web postings:

"Lately I've been having some really [b]strange dreams[/b], they seem very realistic and filled with colour and sounds, ....a few night's ago I had this dream where I saw this very evil, very creepy canine's face coming toward's me, and I heard someone say "shoot!," either way everything went black and I could feel my whole body jerking and shaking, and while this was happening I could hear very loud and very distinct gunshot's, mostly machine gun fire... I found it very weird and woke up immediately after feeling a little disoriented... ."



As many others have already pointed out, this blog post is seriously flawed—no definition of massacres provided, unclear what the graph actually represents, etc. But there’s already some pretty decent research on mass murderers or “rampagers”, so it seems like this guy is trying to reinvent the wheel. The Secret Service has published a few studies on school shooters, and James Fox and Jack Levine have written a few books on mass murder. The research by Grant Duwe, which was referenced above, also seems to have a bearing on this issue since he actually controlled for things like population growth in calculating the mass murder rate. Duwe found that the mass murder rate was relatively high during the 20th century except from about 1940-1965, when it was lower. This trend, he points out, is pretty similar to what we see for homicide, so maybe the macro factors that affect rampages aren’t all that different from those for murder overall.

Duwe doesn’t do any formal hypothesis testing in his research, which is kind of disappointing, but he argues that during the 1940s and 1950s, more men had greater access to the American Dream because more were working, going to school, getting married, starting families, buying homes, going to church; i.e., a greater involvement in conventional activities, stake in conformity, etc. Plus, he reminds us that for a lot of men during the 1940s and 50s, their perspectives were shaped by the depression and WWII, so having a job, a family, and a home seemed pretty good to them. Duwe basically takes a different approach here in that instead of trying to explain why massacres were more prevalent before the 1940s and after the mid-1960s, he tries to explain why they were lower from 1940-1965.

And when we take the longer historical view into consideration, we see what is perhaps another flaw with Turchin’s graph—by starting the trend in the 1940s, it conveys the impression that massacres weren’t very common and have been on a nearly constant increase, which isn’t the case according to Duwe’s research.



There is a chart here for the same time period showing population growth in the US.

http://www.usatoday.com/news/graphics/300million_popcha rt/flash.htm

The increase in population does not account for the upswing in massacres.

Huh? According to the site you link to, the population has roughly doubled from 1950 to now, which is almost the same time period shown on the rampages chart. That alone would cut the apparent effect in half. And that's just one problem with this blog post -- obviously, there are many other problems, as people have pointed out above. So the population increase does undermine the post.


I don't know much about workplace random-ragers('going postal'). Though the surviving school shooters are remarkably unanimous when ask why they did it:

Wayne Lo, 18, Simon's Rock College, Great Barrington, Massachusetts, 12-16-92; 2 dead, 4 wounded

-- "At the time I thought I did the right thing," he said recently. "But as I look back at it over time, more and more it doesn't make sense to me. And more and more I ask myself, Why? Why did I do it? I mean, Why?"


Barry Loukaitus, 14, Moses Lake, WA, Frontier Jr H.S., 2-2-96, 3 dead, 1 wounded

"Barry never articulated a reason why he did what he did." --John Knodel, Grant County prosecutor who handled the case.


Jillian Robbins, 19, Penn State U, State College, PA, 9-17-96, 1 dead, 1 wounded

--when she was arrested, she answered repeatedly, "I don't know." when asked why she brought school violence back to PSU.


Luke Woodham, 16, and Grant Boyette, 19, Pearl, MS, Pearl H.S., 10-1-97 2 dead, 7 wounded

...(I) fought with myself because I didn't want to do any of it."


Michael Carneal, Paducah, KY, Heath H.S., 12-1-97, 3 dead, 5 wounded

Carneal's home room teacher reported that Carneal did not seem to recognize what he had done."

--When ask why he did it, he said he didn't know.


Mitchel Johnson, 13, and Andrew Golden, 11, Jonesboro, AS, Westside Middle School, 3-24-98, 5 dead

--"Since that day, when the boys have been asked the same question(why did they shoot), they appeared not to be able to give an answer." Johnson: "I really thought that no one would actually be hurt."


Andrew Wurst 14, Edinborough, PA, 4-24-98 Parker Middle School(at off-campus school dance); 1 dead, 3 wounded

--"Why did he do it? Andrew doesn't know, ...saying he had no reason of kill the teacher." "...no one...that evening could recall anything that might explain what happened. Andrew himself has no explanation."


Kip Kinkel, Springfield, OR, Thurston High School, 5-22-98, 1 dead, 7 seriously wounded

--In police interview he repeated "over and over" that "I had no choice."

Q: Why did you go to school and start shooting people?

A: I had to. I had no other choice. I couldn't do anything else.


Todd Cameron Smith, Taber, Alberta 4-27-99 W.R. Myers HS, 1 dead, 1 wounded

In a signed police statement, the boy later said: "I have no particular reason for shooting the boys that I did. I don't know who any of them were."


T.J. Solomon, 15, Conyers, GA, 5-20-99 Heritage High, 6 wounded-

--Upon handing the gun over(a teacher had convinced T.J. not to kill himself--the barrel was in his mouth)he started crying hysterically and said repeatedly "I don't know why I did this."


Seth Trickey, 13, Fort Gibson, OK, 12-6-99, 4 wounded

--"He said 'I don't know' when asked why he did it."


Charles 'Andy' Williams, Santana HS, March 2001, San Diego County (2 dead, 13 wounded)

Williams was interrogated by detectives for about an hour after his arrest, and while prosecutor Anton declined to detail what he said, she indicated the statements may not explain why he opened fire.


10-9-06 Memorial Middle School, Joplin, MO

A 13-year-old student walked into the east side of Memorial Middle School, shooting wth a rifle.... (boy's attorney Chuck)Lonardo said the boy's motives and intentions remain unclear even to him after sitting in on juvenile authorities' interview of the boy after the shooting. "That's just it," Lonardo said. "We still don't know.


2-12-07 Suleiman Talovic, 18, SLC Trolley Square massacre, Salt Lake City, UT 5 dead, 4 wounded

Salt Lake City police have finished their exhaustive investigation into the shooting rampage at Trolley Square, finding no real motive for 18-year-old Sulejman Talovic's killing spree. "I think it may have died with him," Salt Lake City Police Chief Chris Burbank said in an interview Sunday with the Deseret Morning News.

Well, I hope that clears things up a bit.


Mike Sandifer

This is patently silly conjecture that does not even rise to the level of formal "hypothesis." There is not enough evidence mentioned to form a plausible hypothesis, much less test one. Focusing on the psycho-pharmacological effects of changes in social status, such as testosterone changes in men, for example, would be more rigorous and likely more fruitful. This is a matter for formal experimentation.

As a side note, the author misuses the word "psychosis" here. Psychosis is clinically defined in the fourth Diagnostic and Statistical manual and generally refers to someone who displays symptoms such as halucinations and severe delusions.


since the total number of rampages in the last 60 years is probably less then 200 , it possible to just gather information on each og the killers in them.

i think using data on each of the masacares and gathering the results could offer better clues to what drove those people to this actions , and should be part of any serious research effort of this phenomenon.


#62 - gun control WILL solve your problem and the 'workrounds' are nowhere near as bad.

Yes, Britain is reeling with horror at a knife crime 'epidemic' that has contributed to 26 teenagers dead in London this year (out of a total population of 7 million people).

In a non-gun owning society, that's a horrifying level of violence to us... Perhaps I'm wrong, but I'd imagine that the (teenange) death rate in American cities is way over that?

I'm with Edward Murrow (#61) in believing that US comment on gun deaths is startling to outsiders and concentrates on anything but the gun.

Reading about students who carry guns to College lectures in the US (as I did recently in, I think, a Slate article) in case of an attack seems like madness to me - my son being a student in London is not likely to face a gunman in his lecture halls, mostly because his fellow students don't have guns.


I agree with Dan Q. Public (the second poster). Basing your statistic on what a newspaper has reported seems none to wise. All you have tracked is what the newspaper reported, not necessarily what has actually happened.


I am as disturbed by the widening gulf between rich and poor as anyone. But the simplistic hypothesis "the rich get richer and the poor get disturbed and go on rampages" is dumb. What about the Great Depression? The nation should have exploded with rampages then. Or how about the financial panics during the Gilded Age - about the time Samuel Colt made all men equal? Don't forget, weapons aren't cheap. Buying a quality assault rifle or amassing a colletions of less destructive weapons takes time and money.

I think the real culprit (beyond people just going crazy) is that life in America is no longer a shared experience across the social spectrum. Back before 1960, Americans felt they were a part of a Democracy that broadly cared for them. Public schools aspired to be more than concentration camps for kids - and often succeeded. People attended churches which provided structure, stability, and contact with their neighbors. Employers that didn't export jobs overseas or depend on illegal aliens and unions provided a backdrop of socialization. TV, radio, and record players provided curious entertainment but didn't necessarily replace plays, dancing, or live concerts where you got to rub shoulders with other people. Nowdays people live in their own bubble of internet, cell phones, ipods. At their jobs they are replacible cogs. They're remote from their communities or at best, interact with communities deliberately remote from the larger community such as street gangs and gated communities. It's been proven in studies that a person who's remotely removed from harming another is far more likely to do so than one close to their victim. I.e., it's far easier to kill a person with a rifle than a knife. But I think it can be argued that psychological distance is also an enabler. A person living in a bubble like I spoke of can, in the depths of their personal rage, emotional disturbance and poor living conditions can more easily determine that people are disposible. In some ways society validates that belief. And certainly there will be fewer people available who can intervene anyway. But before we nostalia binge, perhaps something else needs to be said. While men didn't go bonkers in the Great Depression soup lines, there were negative outlets that the pre 1960's social life enabled. The social oriented outlet for deranged people back then were fascist movements. Black and Brownshirt movements sprang up all over Europe and the KKK revived in America. In the orient, the Japanese went militarist Russia, already totalitarian, just waxed powerful. Finally, gun control is not going to fix this problem. It will ameliorate it some, but the work arounds are too easy. Even now Britain and Japan are reeling from knife violence. And trying to figure a way to ban knives without criminalizing cooks and housewives.



I think the conclusions drawn by Prof. Turchin are questionable. First and foremost, a total of 7 cases per year in a nation of 300M cannot be considered to be significant, statistically or otherwise. These cases are very conspicuous, but quite rare. The increase can be easily attributed to the growth in the US population in the last six decades, or to the more graphic media coverage in recent years (no live TV coverage in 1950, I guess). These explanations are far more plausible, in my mind, than those suggested by Prof. Turchin. Also, he tried to explain acts of madness using economic reasoning, which, again, is not that convincing to me.

Kevin P.

Phil H., you're incorrect.

Our government’s response to the 1996 shooting was to buy around 700,000 guns from their owners, and destroy them. This was not compulsory...

This was a gun ban, followed by a buy back of the newly banned guns.

In the decade since then, Australia has not had a single mass shooting.

Yes, there was, at Monash University, for which, again, law abiding citizens were punished by a further gun ban.

See: http://en.wikipedia.org/wiki/Gun_politics_in_Australia

Joe Torben

Comment #28 nailed it exactly.

Sorry, Freakonomics team, but this was the worst ever blog post from your (usually very interesting) guests. Well, you can't win them all, I guess.

Phil H

Useful fact: Australia had the world's worst mass shooting in 1996: 35 people were shot by a mentally ill man in the island state of Tasmania. In the 15 years prior to that, roughly 1 mass shooting occurred annually, which is a lot for such a small population.

Our government's response to the 1996 shooting was to buy around 700,000 guns from their owners, and destroy them. This was not compulsory, but there was an amnesty unlicensed gun owners who turned their guns in. The government also made it harder, but by no means impossible, to buy guns.

In the decade since then, Australia has not had a single mass shooting.

There's a useful summary here:



There already is a book on this very subject: "Going Postal: Rage, Murder, and Rebellion: From Reagan's Workplaces to Clinton's Columbine and Beyond" by Mark Ames. It was published in 2005. Seems strange Peter Turchin should not have read it.


whatever it is- schools are upping the fear- there is a whole day planned of a replay of columbine- my daughter 15 is scared to even try acting it out.I don't blame her- do you?

wish they would just have talks with the kids- that would be too easy- or difficult?


To study a phenomenon one needs to first define the phenomenon. Massacre wasn't described or well defined above. It was used in the same sentence as "shooting rampages" and "killing sprees." Massacre is usually used in terms of wholesale slaughter of large numbers of defenseless people.

While a family consists of defenseless people, and one could use the term "massacre" in this sense, to me a massacre implys a larger killing.

". . . 57 percent of rampage killers in their database were unemployed when they went on rampage." Two ways to view this, if not more. Your hypothesis and another: perhaps people with "borderline" psychological problems don't work well with other people, can't handle the normal day to day stress we all face.

Therefore they lose their jobs due to their own issues, and then suffer the financial stressors that tip them over.

There are other issues at play here: we are an "all news now" society with cable and satellite, not to mention radio and the ubiquitous Internet broadcasting news into our environs.

As a country we are increasingly smashed together, like rats in a cage, and are in constant proximity with others at work, on the roads, in schools, etc.

While economics may play a role in the issue there are a plethora of other issues to consider regarding this issue.

How many of these killers had their blood examined, either antemortem or postmortem for the presence of psychiatric medications or illilcit drugs? How many of them were prescribed psychiatric medications that they weren't taking?

An interesting topic of conversation.



These numbers are so small, and the increase significantly smaller if you correct for populuation (about doubled) and better news coverage (who knows how much).

And yet, the patten itself is very clear, overall. (btw: the plot is plotted by half-decade, not by decade.)

These rampagers are a handful of people, fewer than 3/100,000,000/year. Let's say that that is the tip of the tip of the iceberg. Should be expect that the rest of the tip or the rest of the iceberg resembles the tip of the tip?

Is this reflective of anthing that affects the the rest of us, or anyone we are likely to meet this year?


No one has yet mentioned that this guest blogger shows up in a blog on the NYT site, and coincidentally, happens to highly privilege as fact (and base his entire hypothesis on) reporting from... the NYT. Huh.


Even neglecting problems with the NYT as a data source and effects of population change, I'm not sure if Professor Turchin's theory meshes well with his data. Assuming his analysis of wages is correct (monotonic increase from 30s to 70s, stagnant thereafter, presumably stagnant before), and that killing sprees responded to wage stagnation, we should see increasing massacres starting in the 70s. Instead, we see a fourfold jump in the 60s, flat numbers of occurrences to the early 80s, and then fairly steady increases to the present.

Even neglecting the jump in massacre incidence in the 60s, why the 10 year lag in incidence between wage stagnation and increased massacre incidence? Also, it isn't clear to me why, if everyone's wages are stagnating, there there is an "unendurable pressure to maintain the socially expected level of consumption". Is it the belief that everyone else's wages continue to increase? Wouldn't this effect wear off after a decade or two?



In my opinion if you want to look at "recurrent waves of violence and political instability" in a society, its not very telling to only look at the crimes most likely committed by people who are seriously mentally unstable and therefore are not a good representation of the society. Why not look at what crimes are more commonly committed? Property theft, political violence, violent crime? The FBI has very good statistics on those going back decades, and using only the NYT and even newspaper stories in general are not a very accurate source of statistics for crime/rampage reporting..you're leaving your statistics up to the whims of editors and other factors such as distance from, space in the paper, lack of information etc..or maybe some of them weren't good stories.

Also your paragraph on stagnating income completely ignores the widespread social benefits we have today compared to the 1930s through 70s. Average people are better off today, its a fact. Also just a straight forward look at the graph shows to me that if people were going to snap in hard economic times..your graph doesn't show much of a correlation between economic booms and busts.