The Skeptics Society & Skeptic magazine

Preventing highly improbable mass murders like that at Sandy Hook Elementary School is impossible, but there are things we can do to decrease violence.

On December 14, 2012, 20-year old Adam Lanza broke into Sandy Hook Elementary School in Newtown, CT, killing 20 children and six adults—and then himself—after first slaying his mother Nancy Lanza in their home. He used a .223 caliber Bushmaster XM-15 semi-automatic rifle in the killing spree, but also had on him a 10mm Glock 20 SF handgun and a 9mm SIG Sauer handgun. He had a shotgun in his car, and at home police found a .45 Henry repeating rifle, a .30 Enfield rifle, and a .22 Marlin rifle, the latter of which he used to shoot his mother in the head four times.¹ All of the guns were legally owned and registered, and preliminary reports note that Nancy Lanza was a gun enthusiast who owned at least a dozen firearms and taught her son how to shoot them at gun clubs in her neighborhood.² Every one of the victims is a heartbreaking story, perhaps best captured by the sole survivor in a first-grade classroom who, after narrowly escaping Lanza’s bullets by playing dead, exclaimed to her mother, “Mommy, I’m okay, but all my friends are dead.”³ Just imagining a first grader uttering those words is beyond horrific.

This article appeared in Skeptic magazine 18.1 (2013).

The response to the tragedy was as emotional as it was predictable, with pundits and the public demanding stricter gun-control measures and more funding for mental-health research and facilities.⁴ The NRA called on Congress to appropriate enough funds to post armed police officers at every school in America.⁵ President Obama pronounced: “We’re going to have to come together and take meaningful action to prevent more tragedies like this, regardless of the politics,” then vowed to do everything in his power to prevent such an event happening again, “Because what choice do we have? We can’t accept events like this as routine.”⁶

That such reactions are emotionally understandable should not distract us from having an objective discussion over whether or not the national obsession over highly improbable events like Sandy Hook is the proper use of our time, energy, and resources toward the overall goal of reducing violence in our society. In fact, the evidence overwhelmingly shows that contra President Obama’s characterization, such events are far more random than they are routine. They are what Nassim Taleb calls Black Swan events.⁷ In this context I shall refer to them as Sandy Hook Events—high profile, improbable, rare and unpredictable mass murders. We cannot and never will be able to predict Sandy Hook Events. We can postdict them, looking for factors common to the killers, but the most we can ever do is make statistically-based generalizations about the likelihood of a Sandy Hook event happening somewhere sometime in the future.

This does not mean we can or should do nothing. It is, perhaps, ironically fitting that the same day as the Sandy Hook tragedy a Chinese man with a knife stabbed 22 children and one adult outside a primary school in the village of Chengping in Henan Province in central China, resulting in zero fatalities.⁸ There really is a difference between a gun and a knife, and in this case that difference is measurable in the number of survivors. However, it is doubtful that Americans would vote to change our government into a Chinese-like authoritarian regime in which controlling guns is possible but at the considerable cost of other freedoms. Nevertheless, we can build a science-based rational response in the form of a two-pronged approach: (1) bottom-up actions by private citizens, experts, and scientists to identify those most likely to commit mass murder and try to reduce the odds that they will do so through various interventions (while recognizing that we can never prevent them entirely); and (2) top-down measures by government, police, and law enforcement agencies to continue the centuries-long trend in the overall decline of violence.

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Figure 1: Mass Shootings in the United States, 1980–2010, tracking incidents, offenders, and victims. In any given year the number of each bounces around wildly, but the overall averages come out to around 20 mass murders and 100 victims per annum.

Murder v. Mass Murder

According to the FBI’s crime reports, between 2007 and 2011 the U.S. experienced an annual average of 13,700 homicides, with guns responsible for 67.8% of those.⁹ That’s an average of 9,289 people shot dead by a gun, or 774 a month, 178 a week, 25 a day, or a little more than one per hour. It’s a disquieting thought that every hour of every day someone is shot to death. By contrast, according to James Alan Fox, Northeastern University Professor of Criminology, Law, and Public Policy, between 1980 and 2010 there was an average of 20 mass murders per year (defined by the FBI as “a number of murders [four or more] occurring during the same incident, with no distinctive time period between the murders”¹⁰) with an average annual death toll of about 100, or 5 per shooting.¹¹ Figure 1 graphs Fox’s data. This averages out to one mass murder every 2.6 weeks, which when clustered in time and covered in explosive media attention intuitively feels like a veritable plague of violence. But an average annual death rate of 100 constitutes a mere 1% of the average homicide total. As well, predicting which week, much less which day and where the mass murders will occur is not possible. If we want to save lives by preventing gun deaths, the larger problem of individual homicides, suicides, and accidents is the place to begin, not Sandy Hook Events.

A 1998 study published in the Journal of Trauma and Acute Care Surgery on “Injuries and Deaths Due to Firearms in the Home,” stated that “every time a gun in the home was used in a selfdefense or legally justifiable shooting, there were four unintentional shootings, seven criminal assaults or homicides, and 11 attempted or completed suicides.” In other words, a gun is 22 times more likely to be used in a criminal assault, an accidental death or injury, a suicide attempt, or a homicide, than it is for self-defense. “Guns kept in homes are more likely to be involved in a fatal or nonfatal accidental shooting, criminal assault, or suicide attempt than to be used to injure or kill in self-defense.”¹²

The raw figures are staggering. According to the National Center for Injury Prevention and Control, in 2010 a total of 19,392 U.S. residents killed themselves with a firearm;¹³ in 2010 there were 11,078 gun-caused homicides and in 2011 there were 55,544 gun-caused injuries treated in emergency rooms;¹⁴ in 2010, 606 people died by unintentional shooting, while in 2011 14,675 were wounded in an unintentional shooting.¹⁵ Ironically—and tragically— the fate of Nancy Lanza was that of most victims of a gun-homicide: killed by her own gun in her own home by someone she knew. The problem is murder, not mass murder; individual homicides, not Sandy Hook Events.

Who Are These Mass Murderers?

Perhaps if we knew more about mass murderers it would ameliorate the problem. Not likely. The pop diagnosis of Adam Lanza as having “Asperger’s syndrome,” for example, whether true or not is irrelevant and unhelpful because millions of people have Asperger’s and related disorders on the Autism spectrum, and 99.99% of them will never commit an act of mass murder. So the moment we turn to diagnostic labels we risk a plethora of Type I false positive errors of suspecting or accusing innocent people.

Perhaps a suite of characteristics or symptoms can help narrow the search. For example, research shows that three of the most common characteristics of mass murderers are:¹⁶

1. PSYCHOPATHY OR MENTAL ILLNESS. Although some forms of mental illness such as schizophrenia have been identified as possible triggers of violent behavior, the best candidate we have for a psychological condition that leads to violence and criminal behavior is psychopathy. According to Robert Hare (Without Conscience), Simon Baron Cohen (The Science of Evil), and Kevin Dutton (The Wisdom of Psychopaths), the latter of whom I queried for this article, “estimates of the incidence of psychopathy tend to vary from 1–3 percent in men and 0.5–1 per cent in women,” and in prison populations, “around 50 percent of the most serious crimes on record—crimes such as murder and serial rape, for instance—are committed by psychopaths.”¹⁷

2. A SENSE OF VICTIMIZATION OR AN IDEOLOGICAL CAUSE. The 32-year old Norwegian Anders Behring Breivik is a case in point: On July 22, 2011, he opened fire on participants in a Labour Party youth camp on Utoya island after exploding bombs in Oslo, resulting in a death toll of 76, the worst tragedy in Norway since the Second World War. He said he did it to “send a strong message to the people and cause maximum amount of damage to the Labour Party to stop a deconstruction of Norwegian culture and mass-import of Muslims.”¹⁸ Perpetrators of violence always have their reasons, including taking the law into their own hands when the state won’t do what they think it should (more on this below in the real causes of the decline of violence).

3. THE DESIRE FOR FAME AND GLORY. Forget American Idol, if you want instant media coverage there is no surer way to gain it in real time than by killing innocent people, especially children. In the case of the Chinese man who stabbed 22 children—reported to be “a long-term epilepsy sufferer” named Min Yongjun who was also “psychologically affected by rumors of the upcoming end of the world”—was quoted as saying: “I learned from the media two years ago that killing children would get me on TV.”¹⁹

There are additional factors that increase the probability of a Sandy Hook Event. According to Columbia University Medical School psychiatrist Paul S. Applebaum: “There are characteristics that when they occur together markedly increase the risk of violent behavior: youth, male gender, substance abuse, paranoid view of the world, hostility and difficulty controlling anger, and preoccupation with weapons. Put those things together and you have identified a group of people who are at much greater risk than the average person of committing a violent act.”²⁰ The problem, Applebaum continues, “is that there are tens of thousands of people who fall into that category and the majority of them will never commit a violent act, and that’s the limit of our predictive abilities today.”²¹

The Prediction and Prevention Problem

Psychopathy is subject to the same false-positive problem. As a back-of-the-envelope calculation, let us employ the mid-range figure of 2 percent psychopathy for men only. The current U.S. population is approximately 314 million, about half of which are males, so if 2% of the 157 million American men are psychopathic, this results in a figure of 3,140,000. Most of these men are not violent; in fact, as Kevin Dutton reveals in his book, many successful CEOs, politicians, Wall Street traders, and special forces soldiers employ their psychopathic personality traits of tough-minded and emotionless impulsive decision making to great effect in the rough-and-tumble world of business, politics, and war. So let’s conservatively estimate that if only 1% of these 3,140,000 men commit any kind of violent act, this results in 31,400 acts of violence per year, a nontrivial number. If only 1% of those violent acts involve murders, this leaves us with 314 tragic deaths caused by psychopaths. And, finally, if only 1% of those murderous violent acts involves killing four or more people in one setting, this results in a rate of 3.14 Sandy Hook Events per year in America. Add schizophrenia, severe depression, and paranoid delusion into the formula and we quite likely have accounted for most of the Sandy Hooks Events.

Perhaps we can just administer the Psychopathic Personality Inventory (PPI) developed by the Emory University psychologist Scott Lilienfeld to everyone and then monitor those who score above a certain number? No. The PPI consists of a wide swath of personality dimensions measured by 187 questions, factor analyzed into a cluster of combined characteristics, such as Machiavellian Egocentricity, Impulsive Nonconformity, Blame Externalization, Carefree Nonplanfulness, and the like. The problem is that most of us have most of these personality traits in some measure. As Lilienfeld told Dutton in an interview, “You and I could post the same overall score on the PPI. Yet our profiles with regard to the eight constituent dimensions could be completely different. You might be high on Carefree Nonplanfulness and correspondingly low on Coldheartedness, whereas for me it might be the opposite.”²²

An additional prediction problem arises from the fact that we find such factors at work in most mass murderers and terrorists after the fact. But before the fact, predicting which individuals who harbor such characteristics will act on them is impossible, and any attempt to target such individuals would result in trapping in our net millions of innocent people who would never act on such impulses. For example, researchers at the University of Connecticut announced on December 28, 2012 that they had obtained a sample of Adam Lanza’s DNA in order to search for a possible mass murderer mutation.²³ This is problematic on several levels. First, it is virtually impossible that violent behavior is caused by a single gene, since no complex behavior studied to date is. The most that can be hoped for is a complex set of genes that code for violent tendencies, which may then be triggered by any number of environmental factors. As such, it is entirely possible— highly probable in fact—that millions of people could have such a gene complex and never act on their violent tendencies, and then we’re back to the problem of Type I false-positive errors in our search, and in the process violate the civil liberties of many innocent people.

What about the brains of mass murderers? Harvard University neuroscientist Joshua W. Buckholtz has studied CAT scans and MRIs of the brains of those who commit acts of violence. He explained in an interview on a PBS Frontline special After Newtown: “When we compare people who commit violent acts against those who do not commit violent acts, some brain differences begin to emerge— differences in brain circuitry involved in emotional arousal and emotion regulation.”²⁴ For example, the prefrontal cortex normally regulates the amygdala— our brain’s emotion center that becomes active whenever a threat is perceived. If the threat is not real, the prefrontal cortex overrides amygdala activity, resulting in no response. But if the circuit between the prefrontal cortex and the amygdala is broken or miswired, the inhibitory signals may be blocked or rerouted, resulting in a false positive response of violence when none was called for, as Buckholtz explained: “In those folks it seems like the circuit is broken in such a way that they are more likely to respond with greater amygdala activity and greater emotional arousal when they think they are being faced with some kind of threat.”²⁵ The problem with brain scan research is that such patterns emerge only after examining a large number of brains, from which computers generate statistical averages that do not apply to any one brain.²⁶

Additional mass murder myths abound that confound the understanding of prediction and prevention. According to the aforementioned criminologist James Alan Fox:²⁷

• Mass shootings are not on the rise, but have held steady over three decades, randomly clustering in time to trick our brains into finding a pattern of increase where none actually exists.
• Mass murderers do not snap and kill indiscriminately, but “plan their assaults for days, weeks, or months. They are deliberate in preparing their missions and determined to follow through, no matter what impediments are placed in their path.”
• Enhanced background checks do not keep dangerous weapons away from mass murderers because “Most mass murderers do not have criminal records or a history of psychiatric hospitalization. They would not be disqualified from purchasing their weapons legally.” And even if they could not legally purchase the firearms needed, “mass killers could always find an alternative way of securing the needed weaponry, even if they had to steal from family members or friends.”
• Restoring the federal ban on assault weapons will not stop Sandy Hook Events because “The overwhelming majority of mass murderers use firearms that would not be restricted by an assault-weapons ban. In fact, semiautomatic handguns are far more prevalent in mass shootings.”
• Mass murderers are unlikely to be deterred by increasing security in public places because “Most security measures will serve only as a minor inconvenience for those who are dead set on mass murder,” as in the case of Columbine, whose armed guard was unable to stop Eric Harris and Dylan Klebold.

Is There Nothing We Can Do?

If we cannot predict or prevent Sandy Hook events, what can we do? I suggest three evidence-based actions we can take right now that could save lives.

1. RUN, HIDE, OR FIGHT. There is an excellent video on self-defense on YouTube called “Run. Hide. Fight. Surviving an Active Shooter Event.”²⁸ It is for people in offices, schools, or any public facility in which gunfire is heard. After calling 911, the first thing to do is to run—escape from the building as quickly as possible, taking as many people with you as you can. If people hesitate, encourage them to join you but leave them behind if they do not move at once. You have seconds to act and cannot afford to delay. If there is no clear escape route, hide underneath a desk, behind a wall or door, or inside any container in which you can fit. If you are in a room, lock the door and barricade it with furniture. Remain as quiet as possible and silence your cell phone. If these two actions do not work and you encounter the shooter, fight with anything and everything you’ve got—a chair, purse, fist, leg, anything you can throw, swing, or hit with. Do not hesitate and attack like your life depends on it because it does. At that moment you will likely either be killed or stop the killer long enough for others to join in.

2. A NATIONAL MENTAL HEALTH HOTLINE. A joint effort between such governmental agencies as the National Institutes of Mental Health, the American Psychological Association, the Association for Psychological Science, the American Psychiatric Association, and the FBI could result in a national mental health hotline for potentially violent psychopaths, schizophrenics, and severely depressed and delusional people who also exhibit behaviors indicative of violence and purchase large quantities of firearms and ammo. A Mother Jones study on “A Guide to Mass Shootings in America,”²⁹ for example, found that more than half (38 out of 62) were committed by individuals with mental health problems who had exhibited signs noticed by family, friends, or colleagues indicative that something was wrong and that violence of some kind was possible.³⁰ Depression, delusion, and paranoia were common features of the killers in this cohort, and 36 of them committed suicide at the end of their killing spree, with another seven opting for “suicide by cop” in a final Götterdämmerung with the police. A national database of people reported as: (1) exhibiting a set of symptoms of mental disturbance such as acute depression, schizophrenia, extreme psychopathy, paranoid delusions, and (2) a clear sign of potential violence such as comments or letters or journal entries about killing people, and especially (3) the purchase of multiple weapons, ammunition, body armor, and other equipment, might be cause for authorities to at least pay a visit to the residence of the person in question.

A case in point is James Holmes, the Aurora, Colorado killer, who showed clear signs of a mental breakdown during the May to July timeframe in which he amassed an arsenal of 6,295 rounds of ammunition, two handguns, a shotgun, an assault rifle, ballistic gear, laser sights and holsters, and tear gas canisters, all delivered to his doorstep.³¹ Competent data analysts working with such a national database could easily ferret out potential mass murderers. This would be something like a citizens watch program in which all of us should be paying attention to the people around us, most notably our immediate family, friends, and colleagues. On the day I was writing this section (January 7, 2013), for example, ABC News reported that an eastern Alabama high school teacher turned over to the police a student journal she found that “contained several plans that looked like potential terrorist attacks, and attacks of violence and danger on the school,” including targeting six students and one teacher by name. That young man, a 17-year old named Derek Shrout, identified in the media as a white supremacist targeting five black students and one gay student, was promptly arrested on attempted assault charges after police searched his home and found numerous cans filled with pellets that, according to the sheriff, were just “a step or two away from being ready to explode,” adding that “the system worked and thank God it did. We avoided a very bad situation.”³² What system? A mass murder was averted thanks entirely to the bottom-up actions of an alert citizen, not the topdown measures of authorities.

Of course, the civil liberties of such individuals would need to be protected, and law enforcement agencies would have to be leery of false charges made out of revenge against rivals, but surely someone reported by close friends, family, or colleagues as having severe mental health issues, who has made violent threats involving mass murder, and who has purchased an arsenal of firearms and ammunition, might at least alert local authorities to be extra vigilant.

3. GUN CONTROL. This is the most talked about option for preventing Sandy Hook Events, but it’s a complicated option with numerous permutations. First, the most common weapon of all homicides and mass murders is a handgun, and the United States Supreme Court ruled in 2008 (in District of Columbia v. Heller)³³ and again in 2010 (McDonald v. Chicago)³⁴ that the Second Amendment’s guarantee of the right to “keep and bear arms” includes handguns. And once the Supreme Court has ruled on a case—twice in this instance—the chances of overturning such rulings are next to nil. In any case, with over 300 million guns already in the homes and on the streets of America, short of turning the United States into the Stasi States wherein police sweep through every home, business, garage, shack, storage unit, cabin, car, and container in every nook and cranny of every state in the union (potentially resulting in Ruby Ridge and Waco-type confrontations with those who resist), gun bans will most likely be honored by the people who least need them and ignored by those who need them most. Even talk of stricter gun control laws following the Sandy Hook massacre has driven gun sales through the roof. A gun show in Ontario, California the first weekend of 2013, for example, was overflowing with customers lined up outside the door to get in, and those who made it inside were snapping up firearms and ammunition at record rates. One customer noted “I’ll tell you right now, Obama is the No. 1 gun salesman in the nation. The NRA should give him an award.” The FBI reported that December, 2012 was the biggest month in their history for the number of firearm background checks conducted, at 2.78 million.³⁵ In one month alone nearly three million people purchased guns.

Here is a typical suggestion for a reasonable gun control measure, from the aforementioned psychiatrist Paul Applebaum:

Even in the face of our difficulties of predicting and preventing violent behavior in general, there is an approach we can take today that will markedly reduce the likelihood of horrific crimes like what occurred at Newtown, CT, where we remove from easy access weapons that are designed solely for the purpose of killing large numbers of people—semiautomatic weapons, high-volume clips, bullets intended to seriously maim and kill their victims. That could have an impact today while we wait for the science to improve, while we wait to have a better capacity to identify people who are likely to behave in violent ways.³⁶

Let’s examine these options in more detail. Banning semi-automatic weapons is not likely to have a significant effect on Sandy Hook Events since most are committed by handguns, and the evidence for the effectiveness of bans on semi-automatic weapons on overall crime rates is mixed. Following the 10-year Federal Assault Weapons Ban enacted in the United States in 1994, the National Research Council (NRC) reviewed all academic studies of the assault weapon ban, concluding that the data “did not reveal any clear impacts on gun violence,” and noted, “due to the fact that the relative rarity with which the banned guns were used in crime before the ban…the maximum potential effect of the ban on gun violence outcomes would be very small.”³⁷

On the pro-gun side of the debate, John Lott, whom I spent a weekend with in Santa Fe, New Mexico at a conference and whose book More Guns, Less Crime has been a steady flashpoint for controversy, argues that gun bans have the opposite effect than intended.³⁸ Take Washington, D.C., he says. Before the ban on handguns was implemented in August of 1976, D.C. ranked 20th in murder rates out of the top 50 cities in America. After the gun ban, D.C. shot up to either #1 or #2, where year after year it held steady as “the murder capital of the nation,” as it as dubbed by the media. As a control experiment of sorts, after the Supreme Court decision in the 2008 Heller case overturned the D.C. gun ban, murder rates dropped and have continued to fall ever since. According to Lott, whose data is based primarily on crime statistics provided by the FBI, once the gun ban was lifted, homicide rates plummeted 42.1%, sexual assault rates dropped 14.9%, robbery excluding guns dropped 34.3%, robbery with guns plunged 58%, assault with a dangerous weapon excluding guns sank 11%, assault with a dangerous weapon using guns tumbled 35.6%, and total violent crime nosedived 31%, along with total property crimes decreasing a total of 10.7%.

Why do more guns mean less crime? Lott says it is because it is hard to keep criminals from getting and keeping guns because gun bans are primarily obeyed by non-criminals. Criminals that already have guns do not turn them in, and potential criminals that want to get guns have no problem procuring them illegally on the street (and in any case most mass murderers obtained their guns legally). Lott cited several studies by criminologists who interviewed criminals in jail and collected data on the amount of time they spend casing a home before burglarizing it. In the U.K., where gun bans are much more prevalent than in the U.S., the criminals reported that they spend very little time casing a joint and that they don’t really care if someone is home or not because they know the residents won’t be armed (whereas they, of course, are armed). Their U.S. counterparts, by contrast, reported spending more than double the time casing a home before robbing it, explaining that they were waiting for the residents to leave. Why? They said that they were worried they would be shot.

Lott has his critics , some of whom resort to ad hominem attacks (such as Piers Morgan and Alan Dershowitz³⁹), while others more thoughtfully challenge his data.⁴⁰ I agree with Lott that gun bans have done little to reduce crime, at least in the United States, but I disagree with Lott that the lifting of gun bans is the cause of the decline of violence in the 1990s and 2000s. That cause is hotly disputed, with everything from the Freakonomics theory (that Roe v. Wade led to fewer unwanted children being born in the 1970s and thus fewer kids growing up in poverty and becoming criminals in the 1990s),⁴¹ to more police on the beat and assorted other factors well summarized by Steven Pinker in The Better Angels of Our Nature.⁴²

The most cited study in support of gun control comes out of Australia following a 1996 firearm massacre in Tasmania in which 35 people were murdered. State governments agreed to ban semiautomatic and pump-action shotguns and rifles. A 2006 follow-up study measured “changes in trends of total firearm death rates, mass fatal shooting incidents, rates of firearm homicide, suicide and unintentional firearm deaths, and of total homicides and suicides per 100,000 population.” The data showed that in the 18 years before the ban there were 13 mass shootings, but in the decade following the ban there were 0. Statistically significant declines were also found for total firearm deaths, firearm suicides, and firearm homicides (but not for unintentional firearm deaths). There was also “no evidence of substitution effect for suicides or homicides,” and “the rates per 100,000 of total firearm deaths, firearm homicides and firearm suicides all at least doubled their existing rates of decline after the revised gun laws.” The authors concluded:

Australia’s 1996 gun law reforms were followed by more than a decade free of fatal mass shootings, and accelerated declines in firearm deaths, particularly suicides. Total homicide rates followed the same pattern. Removing large numbers of rapid-firing firearms from civilians may be an effective way of reducing mass shootings, firearm homicides and firearm suicides.⁴³

Is Australia comparable to America? I have my doubts. The population is much smaller and more homogeneous, and the number of guns already in circulation is orders of magnitude smaller, and the “gun culture” there is nothing like it is in America.

Another common element found among mass murderers is large capacity magazines, most notably at Fort Hood, Texas, on the Virginia Tech campus, and in Tucson at the Gabrielle Giffords shooting where the killer used a 33-round magazine. The prohibition of high-volume ammo magazines seems like a rational response based on the fact that a number of mass murders were ended by bystanders and police when the killers stopped to reload.⁴⁴ As criminologist James Allen Fox noted, “limiting the size of ammunition clips would at least force a gunman to pause to reload or switch weapons.”⁴⁵ The proposed legislation on the table, introduced by Representative Carolyn McCarthy (whose husband was killed in the 1993 Long Island Railroad shooting), is called The High Capacity Ammunition Feeding Device Act, and it would prohibit magazines that hold more than 10 bullets (the maximum now is 100).⁴⁶ That seems reasonable to me, and hunters who claim otherwise can give their game a more sporting chance of escape— if you can’t nail them in 10 rounds they deserve to live.

Figure 2: Homicide rates per 100,000 people per annum in five Western European regions, 1300–2000.⁵¹

Figure 3: Homicide rates per 100,000 people per annum in Nonstate societies v. Western Europe, 1300–2000.⁵²

Figure 4: Homicide rates per 100,000 per year in the United States. Note the dramatic decline in homicides during the assault weapons ban starting in 1994, but also note the leveling off of homicides in the last half of the 10-year ban and the dramatic drop after the ban was lifted.⁵³

Whose Rights?

As a lifelong libertarian I have opposed gun control measures, primarily based on the larger principle of increasing individual freedom and decreasing government intervention. Plus, I’ve been a gun owner most of my life. I was raised with guns—my step-father was a hunter and we shot dove, duck and quail with 20-gauge and 12-gauge shotguns that we owned and kept in the house. Growing up I had a BB gun, then a pellet gun, then a 20-gauge shotgun, then a 12-gauge shotgun (the lower number is the higher caliber gun). We had black lab hunting dogs and we went hunting half a dozen times a year and ate everything we shot, which was especially enjoyable given my dad’s culinary skills with wild game. As an adult, for a quarter century I owned a Ruger .357 Magnum pistol with hollow-tip bullets designed to rip to shreds a human body intruding into my home with intent to harm my family. After I started having marital problems I took it out of the house and eventually got rid of it, having studied the psychology of human violence and knowing the statistic cited above about a gun being 22 times more likely to be used on yourself or a family member than a home invader. I own no guns now, but I am not opposed in the least to those who believe having a gun in the home is the best way to protect themselves and their family.

Even though it is not clear that the two suggested laws banning assault rifles and large capacity magazines over 10 bullets would have a significant effect on mass murders, there could be a net gain, and it seems to me to be no great threat to liberty if we lump them with the already-existing bans on private citizens owning and operating bazookas, tanks, drone aircraft, fighter jets, and nuclear weapons. Bans on semi-automatic assault rifles and high-volume ammo clips will not stop Sandy Hook Events, but there is some evidence that they could curtail the level of carnage, and that strikes me as a rational response that even freedom-loving libertarians can live with. Recall the words of the Aurora, Colorado shooting victim Jessica Ghawi, who was almost gunned down in a shopping mall in Toronto in another mass murder the month before, after which she reflected on her blog: “I was shown how fragile life was on Saturday. I saw the terror on bystanders’ faces. I saw the victims of a senseless crime. I saw lives change. I was reminded that we don’t know when or where our time on Earth will end. When or where we will breathe our last breath.”⁴⁷

The Real Decline of Violence

All of the above is prelude, a rational response to irrational acts. The real decline of violence has wholly different causes that have led homicide rates to plummet from almost 1000 per 100,000 people per year in nonstate societies, to around 100 per 100,000 people per annum in Western societies from the beginnings of civilization all the way up to the Middle Ages, to about 10 per 100,000 each year by the time of the Enlightenment, to less than 1 per 100,000 today in Europe and 5 per 100,000 in America. The evidence for this decline and the factors that caused it are well summarized in Steven Pinker’s 800-page The Better Angels of Our Nature: Why Violence Has Declined.⁴⁸

To give just a snapshot of the evidence to support this counterintuitive thesis, using old court and county records in England—to cite just one study summarized by Pinker—criminologists calculate that rates have “plummeted by a factor of ten, fifty, and in some cases a hundred—for example, from 110 homicides per 100,000 people per year in 14th-century Oxford to less than 1 homicide per 100,000 in mid-20th-century London.”⁴⁹ Similar patterns have been documented in Italy, Germany, Switzerland, the Netherlands and Scandinavia, and by the same order of magnitude: from about 100 per 100,000 to less than 1 between the 14th century and the 21st century, as seen in Figures 2 and 3.⁵⁰

Pertinent to current events, Figure 4 shows homicide rates per 100,000 per year from 1950 to 2010 in the United States. Gun control advocates will note the dramatic decline in homicides during the assault weapons ban starting in 1994, but pro-gun advocates can point to the leveling off of homicides in the last half of the 10-year ban and the dramatic drop after the ban was lifted. The conclusion from this data confirms the NRC’s conclusion noted above that the ban had little to no effect either way on homicides.

As for wars, prehistoric peoples were far more murderous than states in percentages of the population killed in combat, as Pinker told me: “On average, nonstate societies kill around 15 percent of their people in wars, whereas today’s states kill a few hundredths of a percent.” Pinker calculates that even in the murderous 20th century, about 40 million people died in war out of the approximately six billion people who lived, or 0.7%. Even if we include war-related deaths of citizens from disease, famines and genocides, that brings the death toll up to 180 million deaths, or about 3%.⁵⁴ Figure 5 presents aggregated data compiled by Pinker from multiple sources for the percentage of deaths in warfare for prehistoric peoples v. modern hunter-gatherers v. modern hunter-horticulturalists and other tribal groups v. modern states. The difference is striking.⁵⁵

Figure 5: Percentage of deaths in warfare for prehistoric peoples v. modern hunter-gatherers v. hunter-horticulturalists and other tribal groups v. modern states.⁵⁵

It would behoove us to consider the fact that this long-term precipitous fall in violence occurred even while the quantity and efficiency of deadly weapons evolved into the killing tools they are today.

Why has violence declined? The English philosopher Thomas Hobbes famously argued in his 1651 book, Leviathan, that violence would be commonplace without a strong state to enforce the rule of law. As he conjectured, in one of the most famous passages in political philosophy:

In such condition, there is no place for industry; because the fruit thereof is uncertain: and consequently no culture of the earth; no navigation, nor use of the commodities that may be imported by sea…no arts; no letters; no society; and which is worst of all, continual fear, and danger of violent death; and the life of man, solitary, poor, nasty, brutish, and short.⁵⁶

Hobbes was only partially right in advocating top-down state controls to keep the worse demons of our nature in check. Trade and commerce was also a major factor, given the moral and practical benefits of trading for what you need instead of killing to get it. I call this Bastiat’s Principle: where goods do not cross frontiers, armies will, but where goods do cross frontiers, armies will not. I call it a principle instead of a law because there are exceptions both historically and today. Trade does not prevent war and interstate violence, but it attenuates its likelihood.⁵⁷

There are many other important sources that contributed to the decline of violence, such as classical liberalism, book publishing, knowledge diffusion, and education, all of which led to the Age of Reason and the Enlightenment, the rise of science and technology, and the Industrial Revolution, but arguably more important than these and as important as the Leviathan state and gentle commerce was a cause identified by a man Pinker calls “the most important thinker you have never heard of”—Norbert Elias—whose book The Civilizing Process documents its title thesis over the course of many centuries, as Pinker explains:

Beginning in the 11th or 12th and maturing in the 17th and 18th [centuries], Europeans increasingly inhibited their impulses, anticipated the long-term consequences of their actions, and took other people’s thoughts and feelings into consideration. A culture of honor—the readiness to take revenge— gave way to a culture of dignity—the readiness to control one’s emotions. These ideals originated in explicit instructions that cultural arbiters gave to aristocrats and noblemen, allowing them to differentiate themselves from the villains and boors. But they were then absorbed into the socialization of younger and younger children until they became second nature.⁵⁸

That second nature is expressed in the unreported “10,000 acts of kindness,” as Stephen Jay Gould memorably styled the ratio of the number of benevolent interactions among people to every hostile act. We have a dark side, it’s true, but we have a second nature as well that is the glue that binds us all in, as Abraham Lincoln so eloquently expressed it, “every living heart and hearthstone all over this broad land” through “the mystic chords of memory” that he envisioned would be touched again by these better angels of our nature.

Poetic prose aside, if we really want to reduce violence, social science research shows that what we should be focusing our attention and resources on maintaining and improving in Western societies and establishing in developing countries:

• The rule of law and property rights.
• Economic stability through a secure and trustworthy banking and monetary system.
• A reliable infrastructure and the freedom to move about the country.
• Freedom of speech, the press, and association.
• Mass education.
• Protection of civil liberties.
• A robust military for protection of our liberties from attacks by other states.
• A potent police for protection from attacks by other people within the state.
• A viable legislative system for establishing fair and just laws.
• An effective judicial system for the equitable enforcement of those fair and just laws.⁵⁹

The effects of these factors over the centuries go mostly unnoticed by our minds, geared as they are to perceiving Sandy Hook Events, but science shows that these are the most reliable means of bending the arc of the moral universe toward truth, justice, freedom and peace.