Every 25.3 seconds, a violent crime is committed somewhere in the United States. Elsewhere in the world, rates of violent crime are even higher.

The propensity for violence is inherent in every human being. However, it is up to the individual to decide whether to act upon this urge or not, which brings us to one of the oldest and most hotly debated topics in psychology: the nature-versus-nurture argument. Is violence caused by the genetic makeup of the aggressor, or is a person’s environment to blame? Those arguing in favor of nature cite numerous studies showing that certain genes increase the likeliness of violent tendencies in a human being. However, many other studies show a link between the environments of certain individuals and the violence they commit. This leaves us with a burning question: why do humans commit violence against each other?

Those who believe that society is to blame for violent acts often cite the Milgram experiment. Three months after the start of the trial of Adolf Eichmann, a notorious Nazi war criminal, Stanley Milgram devised an experiment that would answer a popular question at the time: “Could it be that Eichmann and his million accomplices in the Holocaust were just following orders?” In the study, each volunteer was introduced to an actor (posing as another volunteer) who was strapped into a machine that would deliver electric shocks to his body. The volunteer was subsequently taken to a machine with many small levers, each with its own corresponding shock value, and given a list of questions to ask the actor. With each wrong answer, the volunteer was to shock the actor with increasing severity. As the voltage reached an unsafe level, the actor began to shriek and demand to be released. If volunteers expressed reservations, they were firmly told to continue by the conductor of the study. Eventually, voltages reached supposedly lethal levels, and the actor stopped responding. In the study, 65% of participants went to the highest dose of 450 volts, while all the participants reached 300 volts.

When asked about the study, many volunteers expressed outrage at the conductor’s callous attitude toward the actor’s health, but claimed they could not stop administering the shocks because they had been instructed to continue. The study proves that humans are willing to abandon their morals if an authority figure tells them to. Due to centuries of evolution as social, tribal animals, humans often believe that people with authority are always right. This forces us to consider an uncomfortable possibility: could it be that ordinary, peace-loving people can commit horrifying acts of violence against one another, just because an authority figure commands them to do so? Do we all have the capacity to commit the same kind of atrocities that Eichmann and his fellow Nazi sympathizers committed? Indeed, we can draw some parallels between the subjects in the studies, who absolved themselves of all responsibility before supposedly delivering several lethal shocks to another human being, and Eichmann, who once said, “I was not a responsible leader, and as such, do not feel myself guilty.”

Another fact that supports the nurture argument is that children’s environments significantly impact the likelihood of their growing up to become violent offenders. In a World Health Organization (WHO) report on child abuse, statistics illustrate that an adult who was abused as a child is much more likely to become violent than one who was not. The report shows that “one in six maltreated boys and girls go on to become violent offenders,” while only one in twenty children who are not abused grow up to become violent. This creates cycles of violence in communities that are very hard to break.

The Milgram experiment and WHO report provide some startling evidence that heavily favors those who argue that society is the cause of violence. However, another study suggests that aggression and rage are deeply ingrained in the human body, specifically the human genome. Studies linking aggression to genes began when, while studying a Dutch family that had a history of violence, scientists found that all the aggressors in the family had a common genetic disorder. They all had a defective gene that produces monoamine oxidase A (MAOA), an enzyme that affects the neurotransmitters dopamine, norepinephrine, and serotonin. An excess of these neurotransmitters leads to rage and, subsequently, violence. The mutant version of the CDH13 gene produces similar results.

Another study showing that violence can be blamed on the human genome was done at the Western New Mexico Correctional Facility. Carried out by Kent Kiehl, a neuroscientist at the University of New Mexico, this study consisted of scanning violent inmates’ brains while they were asked to associate a level of moral offensiveness with certain phrases, which activated parts of the their brains. Kiehl studied the brain activity for signs of mental illness. He found that these violent individuals were far more likely to have mental disorders, like psychopathy, than the general public. And because around 50% of these disorders are caused by genetics, there is an indirect link between genetics and violence.

Another way that violence could be related to our genetics can be seen by observing our closest genetic relatives: primates. Primates display aggression in order to establish a stable dominance hierarchy and in response to competition for food, mating partners, and habitat. Perhaps violence is just an instinctive response to such external stimuli. Perhaps our brains are just hard-wired to flood our blood with adrenaline and cause us to have a fight-or-flight response every time we experience any of these stimuli. Perhaps we cannot help it.

Due to the negative effects of violence, there are worldwide efforts to combat aggression in future generations. For example, UNICEF has been conducting various programs to curb violence against children. However, it does make sense to add a small side note: violence is ingrained in the human psyche. We cannot hope to live in a violence-free utopia without compromising basic freedoms, such as free will. As violence stems from a desire to inflict pain on others, the only way to eradicate it would be to quash that desire in all humans. That would mean regulating what we can and cannot feel, effectively shutting down free thought.

Theoretically, we could edit violence out of our genomes. With the advent of gene editing tools like CRISPR-Cas9, scientists are able to delete entire genes from our bodies. Genetic researchers are currently mapping every gene in our bodies to their respective functions. We could cut out the CDH13 gene and all others that are related to violence. Alternatively, we could block the neural pathways that lead to violence. The Connectome, which is essentially a map of each neuron pathway in the brain and its functions, could be used to identify which pathways to block, and nano-technology could be used to block them.

However, these methods raise two problems: what if the absence of these genes affects the body in adverse ways, and more importantly, could this technology be used to curtail an individual’s free will? In the hands of autocratic governments, such science could be used to create a docile society that would submit to every whim of the leaders. Or, it could be used to cause the opposite effect, modified humans whose sole purpose is to cause pain and suffering to others. By implementing these sorts of solutions for good, we are effectively introducing the world to technology that could be used by malicious entities to bend human nature to their advantage.

Violence is an issue that has plagued every life form since the first microbes developed in the oceans. Eradicating it would certainly be a difficult task, as the scientific community would first have to solve the nature versus nurture debate. As shown by the amount of evidence for both sides, this is certainly not a simple decision. Even after the debate ends, one moral question will remain: are we willing to give up our free will and our genetic code in order to eradicate violence?

Sources:

McLeod, Saul. "The Milgram Experiment." Simply Psychology, 2017. https://www.simplypsychology.org/milgram.html.

Parshley, Lois. "Can Your Genes Make You Kill?" Popular Science, April 28, 2016. https://www.popsci.com/can-your-genes-make-you-kill.

University of Barcelona. "A New Study Identifies 40 Genes Related to Aggressive Behavior in Humans and Mice." ScienceDaily, July 9, 2018. www.sciencedaily.com/releases/2018/07/180709101117.htm.

U.S. Federal Bureau of Investigation. "2016 Crime Clock Statistics." https://ucr.fbi.gov/crime-in-the-u.s/2016/crime-in-the-u.s.-2016/figures/crime-clock.

Violence and Injury Prevention Programme. "The Cycles of Violence." WHO Regional Office for Europe, 2007. http://www.euro.who.int/__data/assets/pdf_file/0008/98783/E90619.pdf.