Two horrible mass shootings in a short amount of time this past weekend in El Paso and Dayton have unleashed the normal bad arguments and excuses. This a quick post about how to parse the worst ideas from the better ones. It starts with an annoying but important earworm from Sesame Street:
One of these things is not like the others;
One of these things just doesn’t belong;
Can you tell which thing is not like the others
By the time I finish my song?
I have written several posts over the last 20 months about the statistics of gun violence, and I recognize that correlation versus causation can be a difficult concept. But my Twitter feed today is filled with “causes” that just aren’t, and that Sesame Street song can help you figure this out.
The method is simple: before advancing your favorite “cause” of gun violence in the United States, first ask yourself whether this “cause” exists in other countries that are not experiencing our levels of gun violence. Look instead for places where the U.S. experience of gun violence “sticks out,” where “one of these things is not like the other.” Here are a few “causes” that show up as fallacious in this test:
Mental illness. It is a problem in the U.S. But mental illness is common across the developed world, where gun violence rates are tiny fraction of the U.S. rate. If there is any significance here, it is that several other countries, through truly universal and comprehensive healthcare systems, are far more effective in addressing mental illness than we are. The reality is that mentally ill people are more likely the victims, rather than the perpetrators of gun violence. So, a solid “Buzz, you’re wrong!” here. 
Video games. I don’t like violent video games and don’t play them. But they are universal across the developed world. There simply is no significant correlation here.
The decline of religion and the traditional family. It is usually fundamentalist Christians making this argument. I consider myself a Christian, but having lived in Europe where active membership in a religious community has been going down for decades, I see no statistics correlating this with increases in lawlessness or violence. Indeed, the most religiously “fundamental” places in the U.S. do have a correlation with higher levels of violence.
“Illegal” immigrant gangs. As I have recently noted, presenting oneself for asylum at the border is never a crime under international law, and first-time entry into the U.S. without a proper visa is a low-level misdemeanor (making our current treatment of these men, women and children even more profane). Add to that the large body of evidence of zero or negative correlation between undocumented aliens and crime rates. Gun violence among “legal” Americans is correlated with other types of crime, but the racially-infused anti-immigrant hate is very much misdirected.
So, what are the correlations with gun violence?
I have covered these in detail in other posts with supporting evidence, but the high correlation factors are these:
Guns owned per household. I have made this case in several posts, but guns appear to “go off” at a very predictable rate eerily similar to the mathematics of a classic random lottery, because that is what they are designed to do. And people die as a result.
“High-lethality” gun and ammunition ownership rates. The recent Dayton, Ohio, mass shooting involved a particular large-capacity ammunition clip and the number of people killed within a very short amount of time was a direct result of that configuration. Guns that are designed to cause as much damage as possible do exactly that. We endlessly debate the language of “assault rifle” but gun industry design and marketing research possesses tons of data on what are effectively “lethality effectiveness rates” for the weapons and ammunition they sell. These are the relevant data in this debate.
Gun training and security. Countries that do have high per-capita gun ownership rates, like Switzerland, also have very tight laws regarding registration, training, and the maintenance of a secure location for firearms, as well as heavy restrictions on “high-lethality” weapons. All regulations you might find, unsurprisingly, in a “well regulated militia” should we ever choose to fulfill that constitutional requirement.
Suicide rates. I have written in the past about an Army study that demonstrated the wide variance in suicide rates among its bases worldwide (an amazing and troubling 10 to 1 comparing worst to best practice) is primarily due to the availability of off-duty weapons. Outside of the military as well, suicide by gun is most correlated not with mental illness, but rather with easy gun availability at one’s weakest moments.
Genetics. I don’t give credence to most “men vs. women” arguments in public policy (most are fallacious), but “the data don’t lie!” The large majority (~85%) of domestic homicides are perpetrated by humans with “XY” chromosomes (cough, cough, men) and the sizable majority of the victims (~72%) have “XX” chromosomes (women).  We are so inured to this reality that we assume that “this is just the way it is,” but let me suggest that there is a constitutional “equal protection” argument to be made here.
There you have it. Some stuff is “like the other” and some stuff isn’t. Research the difference.
- I addressed this last year more comprehensively in a post entitled, The “mentally-ill shooter” fallacy.
- Kivisto, Aaron J., et al., “Firearm Ownership and Domestic Versus Nondomestic Homicide in the U.S.”, American Journal of Preventive Medicine, 22 July, 2019.