As humans, it's only natural for us to search for explanations in the face of senseless violence. So it's no surprise that people have floated many weird and offensive theories to explain the tragic shootings late last week at a movie theatre in Colorado, that left 12 people dead and dozens more injured.

But you don't need to look too far for a "reason" to explain this type of violence. Clearly, anyone who lashes out in such a heinously disproportionate way must have a deeper, underlying psychological problem — one that's already been defined in the scientific literature. And James Holmes is absolutely no exception.

While it's still early in the investigation, and with so few clues for us to consider, it's difficult to know exactly what's wrong with Holmes from a neurological perspective. His recent court appearance, with his dazed look and shock of dyed red hair, did little to dispel any notions that this man isn't completely right in his head. And the accounts that he was denied membership at a gun club and that he may have been playing the part of some twisted Batman fantasy don't do anything to dispel that notion.

So based on so little, aside for his penchant for dishing out an unspeakable amount of suffering, what can we say about Holmes, and any neurological problem that may have driven him to kill?

There are three potential explanations, and possibly a combination of these: James Holmes is either a psychopath, a schizophrenic, or he's currently experiencing brain damage (either from an injury or a brain tumor). Let's consider each of these.


The most likely explanation is that Holmes is a psychopath — one who ranks very highly on the Hare Psychopathy Checklist (HPC), a tool that's often used by the FBI to scale the severity of someone who's potentially suffering from the personality disorder.

Psychopathy, like other neurological disorders and conditions, follows a spectrum. The vast majority of psychopaths, who account for 1-2% of the total population, are completely able to keep their urges in check, often channeling their total lack of empathetic awareness into fruitful directions. It's known, for example, that 3-5% of all CEOs are psychopaths.


But clearly, some individuals are more seriously affected than others. The HPC describes a severe category of psychopathy in which individuals exhibit a strong antisocial personality, a penchant for criminality, and a tendency towards reactive anger and impulsive violence. Considering other typical characteristics of psychopaths, including the complete inability to sense pain or fear in others, it's a good bet that Holmes applies to this category.

Psychopaths are also often implicated in what's called "instrumental" violence (i.e. acts of violence that are planned out), as opposed to emotional, non-premeditated outbursts resulting in violence.

It's also worth noting that intelligence has very little correlation with psychopathy, one way or the other. If anything, these individuals tend to express a kind of superficial charm and a tendency towards cunning manipulativeness — what could be construed as a kind of intelligence. Despite everything that's been said about Holmes's supposed high level of intelligence, a claim that appears dubious at best right now, it's a complete non-factor in the equation.


There has also been talk that Holmes is a "sociopath." This is not a clinical term and it should not be used to describe whatever drove Holmes to this act.

Looking into the brain itself, neuroscientists have implicated the amygdala when accounting for psychopathy and impaired empathetic function. This is the part of the brain that's responsible for stimulus-reinforcement learning and responding to the emotional expressions of others. It's also involved in the formation of punishment and reward associations.


Another possibility, albeit one that's more unlikely, is that Holmes is schizophrenic. This condition impairs a person's ability to make sense of the world around them on account of hallucinations and wildly exaggerated ideations (i.e. impaired insight). If you've seen a homeless person wandering around muttering or even screaming to themselves, then you've likely seen a person dealing with schizophrenia.

From a neurological perspective, people suffering from schizophrenia exhibit impairments in the frontal lobes, hippocampus, and temporal lobes. Scientists have observed that these parts of the brain have reduced brain volume — at times even worse than those experiencing Alzheimer's.


Why this condition is more unlikely for Holmes than psychopathy is that people with schizophrenia tend to be more "disorganized," due to the severity of the condition. Their inability to grasp reality often prevents them from engaging in consistently meaningful activities. Holmes clearly exhibited a high degree of organization, since he spent months of methodical planning before his attack. Moreover, people with schizophrenia are not usually violent.

Now that said, it may be possible that he is suffering from both schizophrenia and psychopathy — and that he has somehow been able to remain functional in spite of it. In fact, should the rumors that he fancied himself as a kind of Joker character prove true, it's conceivable that his delusional frameworks were the result of schizophrenia — with his desire to act fueled by extreme psychopathy.

It's worth noting that Anders Breivik, the Norwegian who massacred 69 people one year ago, was not assessed as a "psychotic," but rather as someone suffering from extreme narcissism. The term psychotic, which is not to be confused with psychopathy, is used to describe someone who has lost contact with reality; its wide girth can apply to anyone suffering from schizophrenia, to a person dealing with a bioplar disorder (it's because of this vagueness that some professionals dislike the term altogether). With psychosis ruled out for Breivik, and with the characterization of his personality as an extreme narcissist, it's likely that he's a psychopath. But he's also suffering from something that's not really talked about in this context: a twisted ideology. The combination of the two clearly proved deadly.


With Holmes, there has been some suggestion that he's suffering from psychosis and is currently going through some kind of manic episode right now. While this is clearly a possibility, it's worth remembering that Holmes had been planning the attack for a considerable amount of time — a set of actions that are inconsistent with bioplar disorder and mania. With Holmes, it was likely the intermingling of psychopathy with some sense of warped mission (caused by what, we do not know), that led to his actions.

Moreover, his erratic behavior in court (he's been spitting at corrections officers and using bags as puppets) may actually be an act on his part to show that he is psychotic — a classic sign of psychopathic manipulativeness. Again, these bizarre antics are inconsistent with the degree of sophistication shown in Holmes' planning of the attacks and the booby-trapping of his apartment.

Brain damage

Lastly, there is also the possibility that Holmes has an actual physical impairment in his brain that caused his extreme lack of judgement and the urge to mete out tremendous violence. While psychopathy is predominantly a genetically determined condition, it can also come about as the result of brain trauma. Specifically, psychopathic traits, particularly lack of empathy, can arise after damage to the orbitofrontal cortex (the front part of the brain).

It's also possible that he has a brain tumor — a scenario that was recently considered by neuroscientist David Eagleman. He wrote that, "Another root of incomprehensible behavior can be a brain tumor, such as the dime-sized tumor impinging on the amygdala of Charles Whitman, the University of Texas tower shooter in 1966."


But speaking to io9, Eagleman made it clear that a brain tumor is an extremely low probability explanation in Holmes's case. "I think a brain tumor is possible but very low likelihood," he said, "I think it would be the last place to put one's chips — really something to consider only when all the other more likely things have been ruled out."

Again, like the possible schizophrenia-psychopathy connection, it's also conceivable that Holmes is suffering from a combination of conditions.

Regardless of any neurological condition that may underlie the actions of James Holmes, it's fair to say that the reasons behind such a horrific act are never straightforward or simple to understand. His behavior is very likely the result of a myriad number of factors, including some that aren't exclusively neurological in nature — including the way he was raised or on account of a traumatic experience he may have endured.


An act as vicious as the one exhibited by Holmes has to be understood as the result of a perfect storm of factors. And we should be thankful that incidents such as this one are, in the whole scheme of things, a very rare occurrence.

Images by Barry Gutierrez and Ed Andrieski/AP, and Kevork Djansezian/Getty Images.