On Mass Murderers

We observe the modern epidemic of mass murder in this country and are shocked. We can’t understand who these (mostly young) men are who take the lives of innocents for no apparent reason. What could possibly drive them to do it?

Seeking reassurance, we search for what makes these murderers different from us. In the wake of yet another horrific mass shooting, we must reassess our understanding of the underlying cause.

We conclude that these killers are mentally ill. Legislators devise laws to prevent people who have been committed to psychiatric hospitals or otherwise judged mentally ill from owning guns. Mental health experts demand more psychiatric services to identify and treat them. Even Dear Abby writes, “The triggers that have led to the plague of mass shootings in this country are the result of individuals with severe psychosis (Bangor Daily News, 11/23/ 2015).” It is satisfying to us to believe that we can identify mentally deranged people who commit these crimes, and that they are not like us.

In Europe and much of the rest of the world, there is another group of slaughterers called Islamic Jihadists. When the recent events in Paris unfolded, the world watched horrified as a small cell of ISIS terrorists indiscriminately gunned down scores of random people. We see this as a political-religious act by radicalized Islamists, not a product of mental illness. But how much difference is there, really, between American mass murderers and foreign jihadist ones?

A recent article in The New Yorker by Malcolm Gladwell (“Thresholds of Violence,” 2015) analyzed the genesis of school shooters in the US. Over the past 20 years, there has been a long series of cases following a similar pattern. One or two young men go into unprotected schools and randomly start shooting unarmed students and teachers. Gladwell points out that since 2012, there have been 140 school shootings in America. Some of these young men, such as Kip Kinkel, had bizarre paranoid fantasies and can be identified as psychotic, but some such as Eric Harris of Columbine fame were more appropriately described as psychopaths. Some came from chaotic and violent homes, but others were loved by their families and un-traumatized. Then there was Adam Lanza. What are we to make of him?

In December, 2012, 19-year-old Adam Lanza shot his mother, then went to Sandy Hook Elementary School where he murdered 20 children and six adults.

Much of what is known about his early life was reported by Adam’s father Peter to Andrew Solomon of The New Yorker. Peter described Adam as exhibiting odd behaviors such as sensory hypersensitivity and social dysfunction from an early age. At age 13, a psychiatrist diagnosed Adam with Asperger’s syndrome and recommended he be home-schooled. In his high school years, he became increasingly isolated and distant from his parents. The only emotion he displayed to them was distress in connection with having to socially engage. Perhaps distracted by the Asperger’s diagnosis and unable to penetrate Adam’s secrecy, neither his parents nor mental health professionals were alert for signs of impending violence.

From the clues he left behind, Adams emotions alternated from anger to despair. Anger may have been the only social emotion he was capable of comprehending. His anger was reflected in his increasing fascination with mass murder, which he expressed only online. In his late teens, he spent much of his time editing entries on mass murderers on Wikipedia. He was aware that he was failing in life and had no future. As Solomon put it, “The more Adam hated himself, the more he hated everyone else.”

It seems reasonable to speculate that his final act was to take the life of his mother, whom he blamed for his problems, and then the lives of children who had the promise he could never realize. If we are to look for causes of Adam’s murderous behavior, they do not lie in Asperger’s or mental illness. It seems clear enough that the key to Adam and the common element behind mass murders is rage.

For the Jihadist, the rage is religious and political. The non-believer is evil and an enemy. He must be destroyed or enslaved. The reward for killing the other is a place in heaven. For a mass murderer like Adam, the rage is interpersonal. It is against an enemy who is, in some way, oppressing or preventing the killer from getting what he deserves. The reward is achievement and fame. In either case, compassion has no place.  

Gladwell’s formulation emphasizes the under-appreciated power of situational or social factors in determining our behavior. He invokes a theory of social thresholds. Each of us has a certain threshold for engaging in various actions, be they violent or benevolent. Take, for instance, a riot. One person in a mob of people who has a very low threshold (perhaps due to a high level of anger) throws the first rock followed by someone with a slightly higher threshold. A social contagion may then set in where individuals who would not have considered rioting get caught up and become participants. If there is sufficient social reinforcement, some people become mass murderers.

One of the most famous social psychology experiments, Zimbardo’s Stanford Prison Experiment in 1971, showed the power of social influence and unchecked authority to turn ordinary people into malevolent prison guards or victimized prisoners. Zimbardo assembled a random group of seemingly normal young men and arbitrarily assigned them to the roles of guards or prisoners. Then, in an elaborate piece of theater, he created an isolated prison environment in which the men were told to follow the rules Zimbardo created. The astounding result was that both groups did not just play-act, but actually became the roles they were simulating. As Zimbardo described it, “the power that the guards assumed each time they donned their military-style uniforms was matched by the powerlessness the prisoners felt when wearing their wrinkled smocks with ID numbers sewn on their fronts.”

Although they stopped short of actual physical abuse, the guards behaved cruelly and with little regard for their prisoner-peers’ humanity. Even the kindly doctor Zimbardo assumed the role of prison supervisor. He was blind to the abusive behavior his social experiment had created until his future wife confronted him from an outsider’s perspective.

What Zimbardo showed was that under the right social circumstances, individuals with generally high thresholds for violent action can become Nazi Gestapo or Abu Ghraib prison guards. Unfortunately, this is the dark side of human social evolution that we have seen played out throughout history. There is nothing unusual in the phenomenon of one group of humans defining outsiders as others who do not warrant compassion or even respect.

The commonality between mass murderers and Islamic Jihadists is that both groups have low thresholds for joining in on unspeakable violence. They then join or are influenced by a social group that glorifies violence. Jihadists operate in response to the social contagion of religious extremism which grows with each atrocity. School shooters and similar murderers are increasingly influenced by a virtual social group and a script laid out by their predecessors such as the Columbine killers. Adam’s social isolation and rage lowered his threshold for joining a virtual group for whom murdering innocents becomes a heroic act.

We do not need to invoke mental illness. A personal sense of rage and social contagion is explanation enough.


Gladwell, Malcolm, (Oct. 19, 2015). “Thresholds of violence: How school shootings catch on.” The New Yorker.

Solomon, Andrew. (Mar. 17, 2014). “The reckoning: The father of the Sandy Hook killer searches for answers.” The New Yorker.

Zimbardo, Philip. (2008). The Lucifer Effect: Understanding How Good People Turn Evil. Random House.

Image via geralt / Pixabay.

Robert Gallon, PhD

Robert L. Gallon, PhD, has taught in the Department of Psychiatry and was a psychologist at the Psychosomatic Medicine Clinic at the Jefferson Medical School. He published The Psychosomatic Approach to Illness (1982). As Chief Psychologist at Eastern Maine Medical Center he worked with the Rehabilitation Medicine Department to found a Chronic Pain Program. He is a Psychological Examiner for the court for involuntarily committed psychiatric patients and a consulting psychologist for the State Forensic Service. Over the course of his career, he has evaluated more than 5000 individuals in a wide variety of circumstances. He is the author of Nine Dimensions of Madness: Redefining Mental Health (2015).
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