How Guns Create Aggression and Kill People

© Josh Sager December 2013


Debates over increasing gun control in the United States often devolve into vitriolic shouting matches, where one side considers guns to be dangerous weapons and the other considers them to be amoral tools. Despite the iniquitousness of this argument, few realize that there is a significant body of sociological and psychological research that proves one side demonstrably correct.

A number of reputable studies indicate that firearms act not just as the means by which people kill, but also as an inciting factor for violence—this incitation is called the “weapons effect.”

Put simply, the presence of a gun at the scene of conflict exacerbates that conflict and makes those involved more aggressive than if no gun is present—this increase in aggression exists even for those who are not planning any violence and those who are not in direct possession of the weapon.

Guns may be amoral, but they also produce a predictable increase in aggression for a statistically significant portion of the population. Because of this increase in aggression, nobody can credibly argue that guns bear no culpability in the violence that is committed with them.


The Weapons Effect

In 1967, a study by Leonard Berkowitz and Anthony LePaige was published in the Journal of Personality and Social Psychology, which pioneered the idea of guns as “aggression-eliciting stimuli.” Volunteers for this study were given electric shocks by research assistants and then given the chance to shock the assistants back, up to seven times. During the experiments, a table was present that held either nothing, badminton equipment, or several guns.

Over a series of 100 volunteer experiments, it was demonstrated that the presence of guns increased the retaliatory shocks given to the research assistants beyond that of the control badminton set or the empty table. This disparity indicates that the presence of guns had some effect on the aggression level of the volunteers and made them slightly more likely to be willing to inflict harm on others.

In 1998, a study by Craig Anderson, Arlin Benjamin, and Bruce Bartholow demonstrated that guns create a “priming effect” on aggression that makes people process aggressive stimuli more rapidly than peaceful stimuli. This study involved priming volunteers with images of either guns or foliage and then asking them to read out a mixture of aggressive and peaceful words, so that researchers could measure comprehension time.

Volunteers who were exposed to guns before the experiment more rapidly reacted to aggressive words than they did to non-aggressive words or the control group did to the very same aggressive words—in short, they were “primed” towards aggression.

In 2006, a study by the Harvard School of Public Health concluded that the presence of firearms in a car increases instances of road rage. When guns are in a car, a driver is more likely to engage in road rage and, in cases where the firearm is visible (ex. in a window rack), other drivers to engage in road rage against the armed car.


It may seem counter-intuitive, but the presence of visible guns in a car causes even those in other cars to act with increased aggression against the armed individual. This tends to indicate that the weapons effect is unconscious and disconnected from any rational assessment of the facts of any one specific situation.


Causal Factors

On a surface-level, many may not understand exactly HOW the presence of guns could make normal people more violent, but there are actually biochemical reasons for this increase in aggression. In 2006, a study by Jennifer Klinesmith, Tim Kasser, and Francis T. McAndrew of Knox University found that the presence of guns can increase testosterone levels—as testosterone is linked to aggressive behavior, this explains the exact mechanism by which guns can incite violence.

Similar to the Berkowitz-LePaige study, the Klinesmith et all study used environmental cues and the willingness to inflict pain on others in order to test its hypothesis. Volunteers were given either a toy gun or a real (unloaded) gun for fifteen minutes in a sterile environment before they were asked to add hot sauce to water that another person was going to drink. In order to gauge testosterone levels, volunteers were also given buccal swabs before and after they were told to interact with the toy/real weapons.


Statistically speaking, the results of this study indicated that the volunteers who were given the real gun put more hot sauce in the water and had larger increases in testosterone than those who were given the toy gun. The presence of a gun stimulates the production of aggression-causing hormones in a way that unfortunately synergizes with the fact that guns are an effective way of carrying out violence.



Given the preponderance of the evidence, it is clear that the pro-gun control side of the debate is correct on this issue: guns are not simply the means of murder but also an inciting factor to the aggression that causes the murder. Whenever an anti-gun control activists argues that guns are simply neutral tools that are only dangerous when given to an already violent person, they are either ignorant of the facts or are intentionally trying to obfuscate the truth.

While the presence of guns is in no way causal with increased levels of violence—many people don’t experience the testosterone-driven aggression from guns—it is certainly a correlative factor in some violent confrontations. This correlation is extremely worrying and strong justification for taking a long and hard look at our country’s extremely lax gun laws.

Guns not only create an unconscious and pervasive heightening of aggression but they also give a person the ability to cause immense harm quickly; as such, we, as a society, must ensure that the laws take such a combination into account—something that we are currently an abject failure at—and limit the accessibility of guns to the people who are most likely to be made aggressive enough to harm others.

33 thoughts on “How Guns Create Aggression and Kill People

  1. Okay….let’s assume that studies in a lab under controlled conditions, etc actually translate into real life. My question then becomes so?

    So what if a firearm does increase aggression?
    You talk about ensuring laws take such things into consideration as if they don’t already take them into consideration. There are many things which turn assault into aggravated assault; possession of a deadly weapon is one of them. Why do we need yet another law to handle such situations?

    our country’s extremely lax gun laws.

    Really ? This is one of the things which makes a pro-rights advocates like me really question your view of reality.

    We have laws against murder, we have laws against rape, robbery, thousands of other crimes — and we have laws against felons in possession, illegal possession of a firearm, possession of a firearm in a prohibited place. Thousands upon thousands of laws across the country and you say we have ‘extremely lax gun laws.

    So what laws would you enact that would stop the next Newtown, Aurora Colorado, the next murder?


    • Your personal bias makes it impossible for you to rationally assess the facts (an extreme conformation bias)–it’s kinda sad and something that you really need help with.

      At least recognize the dangers inherent to the hobby that you love and argue from there.


      • jsager99, Your personal bias towards firearms blinds you the the fact that this article is riddled with lies. The only people who feel aggression towards guns are people who don’t like them. Period.


      • I am not biased against guns, merely able to see the facts surrounding this situation–as to the article being filled with lies, I will stand with the dozens of studies, published in reputable and peer-reviewed journals, over your unsupported assertions.

        P.S. I am a great shot, but that doesn’t mean that I wouldn’t support banning guns for the civilian population. The costs of gun violence are simply too high to justify a hobby for a few percentage points of the population.


      • “I will stand with the dozens of studies, published in reputable and peer-reviewed journals, over your unsupported assertion”

        How about the DOJ/FBI numvbers and Obama’s own study debunking gun control? Oh ya that doesn’t fit your agenda.

        “The costs of gun violence are simply too high to justify a hobby for a few percentage points of the population”

        The constitution isn’t about a hobby so huge fail there. Self preservation is a basic human right. Perhaps when citizen control advocates start placing the blame for the evil acts of humans on those humans more change can take place. you know, other than the 50% drop in the last 20 years that already did.

        Just a few examples…of how did you put it? Oh ya..unsupported assertions.

        I will give you a compliment in actually being honest about wanting ban all firearms, most citizen control advocates don’t have the audacity to say they want to create a world of unarmed victims.


      • Likewise, the personal bias of the original article makes the entire thing impossible for someone on either side of the debate to take rationally. The fact there are so many misleading bits of information (using a study that’s 45 years old when psychiatry and other sciences have progressed so much since then) will drive people who are already defensive to take defensive postures (a-la Jer). Likewise, the way the article was written was only to achieve one goal, to whip like-minded followers of the blog into a frenzy of saying “SEE! I told you so, I told you I was right!” despite the fact that the sources cited are completely absurd. Comparind a board game and a gun? These “studies”, as you put it (I say that’s a stretch because they were conducted to support the pro-gun control side, not to study anything) are not scientific in process or in protocols. As a person who carries a firearm every day, I know from personal experience. Reality is far different from a lab. In fact, the real statistic that people with concealed firearm permits have a fraction of the propensity for violence and crime as the general population pretty much debunks the whole article.


      • @Jer

        The CDC Report should pretty much be considered null and void since Gary Kleck of all people helped write it:

        As gun crime has dropped since 1993, gun control laws being put into effect have increased. Including that Assault Weapons Ban you folks love to pretend didn’t help. But that doesn’t fit your narrative does it? Criminals are afraid of armed citizens right, despite the fact that law enforcement agencies do not collect self-defense information as a matter of course, and any available research depends on limited numbers of surveys and other self-reported information. So you can take people for their word if you want, but I’m going to depend on scientific research.

        We can throw links back and forth all day, but the fact remains that nothing you wrote refuted this article. The presence of a gun still causes aggression and raises testosterone levels in many and guns still kill people.


      • You’re right we could send links back and forth all day. But the only thing that really matters is this. We have a right to protect ourselves,period, and that we do over a half million times a year. FACT. And no one has the right to take that away, especially under the guise of safety..


  2. The costs of gun violence are simply too high to justify a hobby for a few percentage points of the population.

    Care to put some numbers with your claim there Jsager99?

    Especially considering that there are an estimated 35 to 50 million gun owners. Texas alone has nearly 600,000 people legally licensed to carry a concealed firearm.

    And the numbers — from the Texas Department of Public Safety puts the highest percentage of convictions — ALL convictions — for CHL holders at 0.5%. Half a percent of all convictions and those we mostly in the immediate year or two after the license was initiated.

    According to the Bureau of Justice Statistics; there were less than 400,000 firearm related violent crimes (less than 10% of all violent crimes) and fewer than 10,000 firearm related homicides (included in the 400,000 total).

    Yet, the least estimated Defensive Gun Use per year is 108,000 with estimates going as high as 2.5 Million. Clearly defensive gun uses are a positive.

    Nor does that even start to consider the millions of people who compete in shooting competitions or enjoy recreational shooting.

    My problem with the studies is they have very little real world application; just because someone responds one way in a game simulation does not mean they will respond the same way to a criminal or immoral act in real life.

    I’ll ask again — you say we have ‘extremely lax gun laws’ — so So what laws would you enact that would stop the next Newtown, Aurora Colorado, the next murder?


  3. On July 28th, didn’t you indicate that “frontal lobe damage” from “aerosolized lead from leaded gasoline” was the cause of violence in the U.S.? Currently, there are approximately 101.5 firearms per every 100 people in the U.S. which translates into 270,000,000 to 310,000,000 firearms in private hands. The current U.S. population is 317,340,000 with over 80% living in cities and suburbs. That should silence any gun control fanatics that still believe that only “rednecks” and “good ole boys” living in the sticks own firearms. If firearms really caused people to be violent, wouldn’t we be having a civil war right about now since we are number 1 in private gun ownership in the world? Since police in the U.S. and Canada all carry a firearm in plain view on their strong side, why don’t ALL incidents in which police are involved end in violence?

    On April 17, 2013, the Presidents gun control bill was defeated in Washington. On May 28, 2013, a poll conducted by the Daily Telegraph in Great Britain revealed that an overwhelming 82 % of BRITISH citizens wanted their privilege to own handguns returned. On September 9, 2013, two Colorado state senators were recalled and removed from office by popular vote due to their failure to uphold our Constitution after having taken an oath to do so. On November 28, 2013, a third Colorado state senator left office due to imminent defeat from a second recall. Are you going to try deny that these things really happened?

    EVERYONE should desire peace and strive for a safer community. Where gun control fanatics continue to fail is when they lack the ability to see firearms as something other than instruments of death that are only used by criminals. Firearms can prevent crime and violence merely by their presence. Gun control fanatics have an actual phobia of firearms and live under the delusion that if they come out the closet and openly proclaim that they do not like guns that others will think of them as pious pacifists and will assume that they are intellectual. This does not change the fact that their views are based on nothing but their own irrational fear.

    Gun control fanatics are finally starting to realize that not only are they defeated, but that they were always outnumbered and never stood a chance. Most will just simply fade away and find some other cause to crusade for, others may convert and join the Second Amendment supporters and an insignificant minority of them will continue their paranoid ranting and babbling as they sit in their drum circles and pass the joint around.


  4. This was intriguing. Sadly, not many women were in most of the studies, which is also interesting. Women are less inclined to own guns.

    The few women I personally know who own guns, either have them because they served in the military, or they hunt (deer). Of the women I know personally, the two women who served in the military, are definitely more aggressive in terms of self protective attitudes, but both have also agreed with the NY state Safe Act’s prohibitions on certain military style guns and certainly background checks on all sales. The deer hunting woman, who hunts with her husband, has a more negative attitude toward gun regulation.

    Inasmuch as the deer hunting woman is older-middle aged and the veterans are younger, that matches with most of the information in some of the studies offered to read. None of the women I’ve mentioned have military style guns, nor seem to believe they are “necessary”.

    If testosterone and conditioned (conscious or otherwise) reflex, are the reason aggression increases in the presence of guns, all the more reason to regulate. It may be a very small sample, but, judging from remarks on this blog, fewer but more insecure men seem to make up the base, of those who will attempt to demean and discredit, any or all fact based studies; in apparent concern for what they may believe is tantamount to questioning their masculinity.


    • So you know a grand total of three women who own guns. Wow. I think it’s time that we see some real facts.

      Most police officers are men. Most people who work at gun stores and attend gun shows are men. Why is it that we never hear of testosterone fueled gun battles at police stations, gun stores or gun shows?

      Not all women are as lucky as you Deb. Apparently you live in a gated community with lots of big strong men to protect you. If you don’t believe that guns make women safer you should maybe talk to a criminal that’s been shot by an intended female victim.


      • Marie, Jumping to conclusion doesn’t encourage understanding. I spoke of three of the women I know who own guns. That does not preclude knowing others. One of my sons served our country 23 years in the military. He is now a CO at the local jail. He is an avid and active hunter, and keeps up fully with target range practices. I’m assuming he has a normal level of testosterone. His opinion as told to me, is the “apocalyptic” attitude of some gun enthusiasts is not only damaging the reputation of sane gun owners, but in fact feeding on the aggressive and unnecessary attitudes of those who think they have “something to prove”.


  5. Something to prove? Perhaps you weren’t watching the national news last year on April 17th, September 9th and November 28th. Earlier, I forgot to mention July 9th when Illinois became the final state to allow citizens to carry concealed firearms. We started 2014 with all states now allowing concealed carry to varying degrees. It would appear that we have ALREADY PROVEN our point. Gun control fanatics are the ones who have something to prove. They are reluctant to confess that they have a phobia of guns and attempt to hide this by trying to make others believe that they are being rational. They are only fooling themselves.

    Tell your son and the two female veteran friends of yours that I said thank you for their service.


  6. Joe Citizen, your last commentary served only to prove my point. You are still trying to prove how omnipotent you are. The majority of Americans are already all too well aware of the pushes to sanctify ALEC-style carry and usage protections. You, nor anyone else who has written here, have “proven” the necessity, or wisdom of accelerated gun buying or carrying. Quite the opposite. And, just for your edification, writing in caps, is aggressive.


    • Self defense is a basic human right. Nothing to prove. Gun control activists own illogical fears of an inanimate object doesn’t override that. And typing in caps is only”aggressive” if you’re looking for it…. get real.


  7. Jer, You are incorrect.. I and others I know, have no illogical fear of guns or other inanimate objects. “Self defense” is a way over used term used for qualifying the truly illogical fears many radical gun owners use; as they appear to fear for their lives everyday. This to me is nonsensical. I could, but won’t argue with irrational fears, they tend to feed on themselves as much as aggression.


    • You discredit your argument by stating “radical gun owners”…. Your other failing is assuming gun owners live in fear. Are you paranoid for wearing your seatbelt? How about a fire extinguisher? Knowing first aid? Scared you’re gonna drown if you wear a life vest? Its called being prepared…and you might want to look up REAL stats about how many defensive gun uses there really are, the answer might shock you…if you’re not afraid of the truth that is.

      Take care.


  8. Matt Manzella (@MatManz)

    The assault weapons ban expired on 09-13-04. A report by the National Research Council earlier that year concluded that the ban “did not reveal any clear impacts on gun violence outcomes”. Since then, gun crime has still continued to drop in spite of the lack of an assault weapons ban and a dramatic spike in gun ownership and concealed carry permits which you and your minority of supporters like to pretend doesn’t help. I guess that doesn’t fit your narrative does it? If you don’t believe that criminals are afraid of law abiding citizens with guns, why don’t you just ask a criminal. I’ll bet you probably know a few.

    Just because the presence of a gun may cause testosterone levels to rise doesn’t necessarily mean that the individual will become violent. When you see a police officer who you know is armed, do you immediately flee in terror? I don’t know, maybe you do. You should probably get your own testosterone level checked.


  9. The weapons and priming effect have been severely criticized: Here Here

    The Harvard study you bring up (funded by the Joyce Foundation) actually showed that Liberals were more likely to engage in road rage as opposed to somebody carrying a gun in their car.

    Furthermore it doesn’t adjust for conceal-carry permits, how many of the people carrying guns had valid permits to conceal-carry for example and lacked criminal and violent histories? Does the study even address that?.


    • While you are correct that there are studies that contradict the weapons effect, some from very reputable sources, the fact remains that the meta-analysis of the literature finds that the effect is real. This could shift in the future, but today, the general consensus is that it is real.


      • “While you are correct that there are studies that contradict the weapons effect, some from very reputable sources, the fact remains that the meta-analysis of the literature finds that the effect is real. This could shift in the future, but today, the general consensus is that it is real.”

        Could you please provide a citation to the meta-analysis? As well as to any “reputable source” where a general consensus is reached?

        I raise you a study that found CCL holders in Texas were 5.7 times less likely to be arrested compared to the general population for violent crimes. A massive blow to the weapons effect argument.

        This looks solely at people with conceal-carry permits, your study on road rage makes no attempt to differentiate if the people in the study actually had valid licenses to carry a weapon.


      • “While you are correct that there are studies that contradict the weapons effect, some from very reputable sources, the fact remains that the meta-analysis of the literature finds that the effect is real. This could shift in the future, but today, the general consensus is that it is real.”

        Could you please provide a citation to the meta-analysis? As well as to any “reputable source” where a general consensus is reached?

        I raise you a study that found CCL holders in Texas were 5.7 times less likely to be arrested compared to the general population for violent crimes. A massive blow to the weapons effect argument.

        This looks solely at people with conceal-carry permits, your study on road rage makes no attempt to differentiate if the people in the study actually had valid licenses to carry a weapon.

        Honest question, which study do you think is more superior? One which looks solely at permit holders, or one that doesn’t control for conceal-carry permits?


      • If a black family living in your neighbourhood increased violent crime and your chance of being stabbed, would that justify controlling black residences?


      • Right, and everyone has the civil right to own weapons. Drafting laws to remove guns from gun owners is the same violation as drafting laws to remove blacks from “white only” zones.

        In both cases, you’re infringing on peaceful peoples’ activities for your own agenda.


      • Actually, even Justice Scalia stated in his Heller opinion that reasonable restriction of firearms is permissible under the 2nd Amendment–it is not an absolute right, unlike the 14th Amendment equal protection guarantee.

        If gun ownership were universal like you are asserting, imprisoned murderers would have a legal right to carry guns in their cells and there would be no way for the government to stop them without violating the Constitution. Obviously, this is nonsense.


  10. After further research it is noted several inadequacies in all the information.
    1) Guns are not the true precursor. Testosterone is the stimulus. But still does not CAUSE the action of aggression. This research study points that out.

    2) Just as you get ready to eat, sit at the table, pick up a fork does not mean it is a causative factor as you salivation, digestive enzymes increase, eyes dilating, etc. This is a person’s response to the stimuli. There still must be a choice and set of circumstances to make this occur. What is the environment? Is the food your favorite or something you hate. There is still a cognitive action to choose.

    3)Regardless of all research, education, statistics and common sense we still are faced with guns. Nearly 2/3rds of gun homicides are SUICIDES! Still seems it is a personal responsibility issue and we should not blame guns for deaths, forks for obesity and computers for pornography programs. It is the individual and their choice of behavior. This is why alcohol is NOT a defensible position.

    Tay, the AI program lasted 24 hours because it learned from its users. What it learned was to become a Sexist, Hitler loving, homophobe because it took in what WE had sent it. We are the problem, our behavior, not the biochemicals natural or artificial.


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