Ted Bundy. The Zodiac Killer. Jeffrey Dahmer. Jack the Ripper. Richard Ramirez.
Even if you aren’t a true crime expert, you probably recognize at least a couple of the above as some of the most infamous serial killers in history. And for good reason- Ted Bundy, for instance, murdered at least 30 women. And Jeffrey Dahmer was a cannibal responsible for the murder of 17 males.
Considering such a horrific, violent crime like murder, many of us can’t help but wonder about the individuals who have ended a life. What is it about a person that can drive them to commit such a heinous crime? Is there a potential in all of us to kill, or does it take a special sort of human? What truly makes a murderer?
Unfortunately, there isn’t a simple answer to any of these questions. A number of psychological, social, and biological influences likely combine to create a “perfect storm” within an individual that will drive them to commit murder, such as adverse childhood experiences, mental illness, personality disorders, drug abuse, trauma, and brain damage.
But luckily, a recent study has emerged that brings us closer to fully understanding homicidal individuals and their motives for killing.
Lead researcher Ashly Sajous-Turney and colleagues from The Mind Research Network wanted to determine whether there are any differences in brain structure between homicidal inmates and other prison inmates. They selected 808 incarcerated male adults from New Mexico and Wisconsin prisons to participate in their study. From there, each subject was placed into one of three groups based on their criminal history: Homicide, Non-violent Homicide, or Non-violent/Minimally Violent, and then given an MRI scan.
As the research team predicted, the homicide group showed a widespread reduction in brain matter when compared to the other non-homicidal groups, particularly in the major regions involved in emotional processing, behavioral control, executive function, and social cognition. These brain areas take part in what’s called theory of mind, or the ability to assess the perspective and emotional state of others.
Take, for instance, the orbitofrontal cortex. It’s known for its role in theory of mind, and was one of the brain areas seen to have deficits in homicidal individuals. This connection is quite fascinating, as it may help to explain the relationship between killers and a lack of theory of mind.
Although The Mind Research Network’s study certainly is groundbreaking, it does have its limitations. The deficits seen in the brains of the study’s homicide offenders may not necessarily be specific to homicidal behavior; rather, other coexisting conditions could contribute to what researchers found. The study also carries some potential ethical concerns, as brain scans of criminals are currently being used in court. Such scans should not be used alone to identify individual homicide offenders until further research is able to replicate and expand upon the findings of the study.
The abnormal brain differences observed in homicide offenders are key in further understanding the connection between our biology and murder. As Sajous-Turney concludes, this study represents an “incremental step in making our society safer by demonstrating the crucial role of brain health and development in the most extreme forms of violence.”
Featured image via Wikimedia Commons