Guns, statistics, and appeal to authority


Very recently, I was involved in a debate on Facebook about whether guns should be restricted in light of the seemingly above average amount of shootings that have occurred over the course of the past several months. My debate partner kept pushing me to show him statistical information that supported my view that the state’s gun restriction policies are not the answer (not to mention that it would not be ethical). I responded by saying that using statistics for something so complicated such as this would not provide much information since there are so many variables in play. It would be virtually impossible to analyze the effects of gun control and gun ownership ceteris paribus on the amount of subsequent gun violence.

An article from The Guardian called, “Guns don’t offer protection – whatever the National Rifle Association says” was then added to the discussion. It summarizes a 2009 paper written by the University of Pennsylvania’s Prof. Charles Branas that, as per the listed objectives, “investigated the possible relationship between being shot in an assault and possession of a gun at the time.” The data was taken from Philadelphia from 2003 to 2006. Their results showed that “individuals in possession of a gun were 4.46 (P < .05) times more likely to be shot in an assault than those not in possession. Among gun assaults where the victim had at least some chance to resist, this adjusted odds increased to 5.45 (P < .05).”

The results look pretty convincing. The numbers don’t lie, right?

I provided three articles, “Stealth Agencies for Gun Control” by Karen De Coster, “U of Penn ‘study’ authors admit glaring flaw” by Kurt Hofmann, and “Are You More Likely to be Shot Because You Own a Gun?” by Clayton E. Cramer.

Each of these articles picked up on problems with the Branas paper. Hofmann points to a piece from that says:

According to Reason magazine, however, the one explanation the researchers do not mention is that people who anticipate violent confrontations — such as drug dealers, frequently robbed bodega owners, and women with angry ex-boyfriends — might be especially likely to possess guns, just as people likely who jump out of airplanes are especially likely to possess parachutes.

The authors acknowledge that they did not account for the potential of reverse causation between gun possession and gun assault — that is, the possibility that a high risk of being shot causes gun ownership, as opposed to the other way around.

This is crucially important. Like many large cities, Philadelphia has its fair share of crime. Is it the case that the people in the study are carrying guns just in case the situation arises where they need to defend themselves violently? Or is it more likely that many of these gunshot victims carried guns because they expected that they would need them?

Similarly, De Coster and Cramer discuss Branas’ mistake of confusing correlation and causation. Cramer writes:

You probably learned somewhere that correlation does not equal causality. That is to say, just because two variables rise and fall together doesn’t mean that one causes the other. One of the examples is that ice cream cone sales rise and fall with rape rates. It isn’t that ice cream cones cause rape; it is that high temperatures increase demand for ice cream and cause many people to leave windows open to get a cool breeze to enter; instead, a rapist takes advantage of the unlocked window.

Tying this into Branas’ paper and his conclusion that “users should reconsider their possession of guns,” Cramer later writes:

What’s the direction of causality here? Are you more likely to be shot because you own a gun? Does anyone seriously believe that buying a gun attracts criminal attackers? Or do people buy guns because they perceive that they are in danger of being attacked? If it is the latter, they guessed correctly. Someone shot them.

There’s nothing wrong with using academic studies to formulate your opinion. But when the studies that you’re using are shown to contain fatal flaws, it is important to disregard the papers as evidence to support your view. Since Branas’ error only renders his study inconclusive, it doesn’t necessarily mean that your opinion is incorrect.

What was my debate partner’s response to my rebuttal and demonstration of confusing correlation and causation? He merely dismissed the articles as just “some blogs” and made absolutely no attempt to respond to the critiques. Later in the day, he posted the following status to his Facebook page, which was obviously directed at me:

If I’m reading academic research papers, and you’re reading conspiracy blogs, chances are we won’t be coming to a consensus. One of us, however, will be reminded of the meaning of “opportunity cost.”

First of all, he’s making a rather poor attempt at poisoning the well. Assuming he actually read the articles I provided him, it’s very unlikely that he checked any of the sources that were used. He’s dismissing them as if they’re just written by some random guys with no qualifications. He says he prefers material put forth by academics, so it’s rather comical that he would reject work by Clayton E. Cramer on the subject.

But more importantly, his basis for his support for Branas and his rejection of the other material is an appeal to authority. According to him, since Branas is a professor at an esteemed university and has written academic research papers, he accepts what Branas says is true over those who do not hold such credentials. Can such blind faith reliably lead to a well-informed opinion based on reason?

The Asch Effect describes how people, in possession of the opinion of the majority of a group or an authority figure, tend to follow along with that opinion even when the obviously correct information is presented to them. This is the essence of the appeal to authority. In a bit of irony that I can only describe as poetic, the previously mentioned article from The Guardian states that a paper by Prof. Jessica Witt and Dr. James Brockmole found that “where subjects were given either a replica gun or a neutral object and asked to identify the objects other people were holding,” those “in possession of a replica firearm were much more likely to identify a neutral object as a firearm.” My debate partner and those like the author of article from The Guardian harshly criticize those who feel the mistaken perception of power and safety when in possession of a gun. Replace “gun” with “academic research paper” and “power and safety” with “correctness,” and the hypocrisy becomes quite apparent.

Perhaps you may think this debate of mine was a waste of time, but what it did provide was an example of the great lengths that a person will go in order to confirm his own biases.