Experts in psychology, criminology, and neuroscience, including Dr. Scott Bonn, believe that serial killers are “made” through a combination of severe childhood trauma, dysfunctional families, and social factors. It is notable that when you dive into the childhood and upbringing of serial killers, it is highly likely to find cases of physical, sexual, and psychological abuse as well as neglect.
Author: Maxine Wolters
Ted Bundy, Jeffrey Dahmer, Ed Gein. These are all names of some of history’s most notorious serial killers and there’s huge public fascination around them. A question that often sparks up around them is „Are serial killers born evil or shaped by their environment? “. This article explores both the biological and environmental factors to understand whether serial killers are born or made.
A serial killer is an individual who murders three or more people, with the killings taking place over a period of more than one month in three or more separate events. The victims tend to have things in common, such as demographic profile, appearance, gender, or race. While it’s not always clear what motivates serial killers to commit such heinous acts, abnormal psychological processes – notably severe antisocial tendencies – are usually to blame.
Neuroscientist Jim Fallon spent 35 years studying the minds of serial killers. He suggested that three high risk factors could exist in someone without necessarily leading to murder: brain damage, having the MAOA gene, and overexposure to serotonin in the womb. But why are they high risk factors? Head injuries are often linked to violent, repetitive criminal behaviors, particularly to serial killers. In fact, 80% of the most high-profile serial killers such as Richard Ramirez, Glen Edward Rogers, and John Wayne Gacy, have had significant brain injuries. It is proven that head injuries, especially those affecting specific brain regions like the prefrontal cortex and the temporal lobe, can lead to problems with impulse control, emotional regulation, and decision making. Timing plays a crucial role too. Early-life brain injuries, particularly during critical development stages, disrupt emotional and social development, while brain injuries during adolescence often impair impulse control and judgment.
The MAOA gene, nicknamed „The Warrior Gene” due to its associations with aggressive and risk-taking behaviors, is an enzyme called monoamine oxidase A (MAOA), which some individuals have a variant of. It plays a key role in breaking down the neurotransmitters responsible for positive emotions, such as noradrenaline, serotonin, and dopamine. Having levels of MAOA that are too high or too low can have negative effects on our mood and behavior. This gene is more common in men which could suggest why more men are serial killers. However, this gene alone is normally not enough to make someone kill.
Experts in psychology, criminology, and neuroscience, including Dr. Scott Bonn, believe that serial killers are “made” through a combination of severe childhood trauma, dysfunctional families, and social factors. It is notable that when you dive into the childhood and upbringing of serial killers, it is highly likely to find cases of physical, sexual, and psychological abuse as well as neglect. The Mitchell & Aamodt, 2005 research has shown that 50% of serial killers suggest that they have experienced psychological abuse, 36% have experienced physical abuse, and 26% have experienced sexual abuse. Bullying and social isolation are experiences that some serial killers, such as Robert Hansen, also known as the „Butcher Baker“, have had that has contributed to the becoming of a serial killer. This is because many victims become the aggressor later in life to feel powerful and because it builds resentment towards certain groups of people or just towards life in general.
Can serial killers be predicted in their childhood? The MacDonald triad by J.M. Macdonald suggests that these following three signs can indicate whether a child will grow up to be a serial killer: if a child is cruel to animals and may even kill them; if a child sets fire to objects or otherwise commits minor acts of arson, if a child regularly wets the bed. Macdonald claims it is important to note that not all kids who do these things turn out to be a serial killer and that there is no definitive link between these behaviors and adult violence, but that there is a connection.
In conclusion, the question of whether serial killers are born or made does not have a simple answer. It lies at the complex intersection of biological predisposition and environmental catalysts. While genetic factors like the “Warrior Gene” and physical brain trauma can create a high-risk profile by impairing impulse control and emotional regulation, these biological factors alone are rarely enough to create a killer. It is rather a mix of nature and nurture. While many serial killers were once victims of horrific neglect and abuse, these experiences explain the development of their pathology without ever justifying their actions. Understanding this blend of nature and nurture is not about absolving them of guilt but about finding the deep-rooted patterns of trauma and biology that might one day allow for earlier intervention.
Cover image by: ThankYouFantasyPictures from Pixabay
Edited by: Lina Welin; Johanna Larsson Krausová
