The Development of the Psychopathic Serial Killer: Biological and Environmental Factors
Anyone is capable of aggression: athletes in fierce competition, friends arguing, coworkers competing for a position, even toddlers when they are playing in the school yard. For some, this aggression leads to violence, engaging in fights and causing harm to others. Yet, aggression and violence can be more than just throwing a punch; robbery, arson, rape, murder, and terrorism all fall under the broad blanket of “violence.” And clearly, not all violence has the same weight, as punching someone is not the same as beating someone to death. There is a line drawn between these two acts: the law. Obviously, you won’t go to jail for getting into a fight at school or getting a little too hostile with someone. This is not the same story for those types of violent acts labelled criminal, and depending on the crime and its severity, the jail time and possible other consequences increases exponentially. But, the majority of people do not escalate to this type of violence, and while everyone can show aggression, most are able to control it. So, what differentiates us? Why are some more violent than others? How can some individuals become barbaric killers?
There is no clear-cut answer to the above questions; what makes a criminal, and more specifically what makes a serial killer, is not a simple this or that. In fact, this answer has been sought for decades, as some of the early psychologists were perplexed by what can drive humans to act in such ruthless ways.
Through much research, I believe I have compiled the information needed to answer these puzzling questions, though the answer is still not a simple one. Rather, I have come to this conclusion: neurological make-up correlates to criminal behavior by predisposing people to aggression and violence, and this biological factor often acts in unison with external stimuli.
To begin to understand the origins of violence in people, we must first understand violence itself. It is generally known that there are two sub-categories of violence: affective and predatory. Affective violence arises in a defensive response, such as when under-attack. Predatory violence is the opposite, and is distinguished as offensive; the person acts violently because they want to or have planned to do so, and they often lack empathy for their actions, even if these acts cause serious harm to the offender’s victims. To gain a deeper understanding of these two violence subtypes, we must delve into the work of Sigmund Freud. Known for his work in psychodynamics and analytics, Freud offered a similar idea to affective and predatory violence, but instead refer to these two elements as the thanatos instinct and eros instinct, the death and life instinct, respectively. Freud describes the thanatos instinct as a natural destructive force that leads to unconscious guilt and repeated compulsions of aggression and violence. This most closely correlates to predatory violence. The eros instinct aligns with affective violence, as it is based on aggression for survival (Yakeley).
Similarly, psychiatrist William Glasser also had his own approach to the two types of violence: self-preservative violence and sadomasochistic violence. Self-preservative violence models that of affective violence, and is described by Jessica Yakeley, a psychiatrist in forensic psychotherapy and director of the Portman clinic (“Jessica Yakeley”) as, “a primitive response triggered by any perceived threat to the physical or psychological self. Such threats might be external, such as attacks on the person’s self-esteem, frustration, or feeling humiliated or insulted. The person can also feel threatened by internal sources, such as feelings of disintegration and internal confusion that might occur in psychosis. The violent response is immediate and aimed at eliminating the source of danger.” Corresponding to the affective subtype of violence, we can once again see that Glasser’s version is also a responsive violence, not an offensive one. Rather, Glasser theorized sadomasochistic violence as one similar to predatory violence in that, “the object and its responses are of great interest to the perpetrator. The object must be made to suffer, but must be kept alive in order to achieve this. Sadomasochistic violence also involves sadistic pleasure” (Yakeley). Here, Glasser begins to touch upon a common trait found in serial killers — a pleasure in the kill.
Now that we have differentiated violence into two subcategories, we can begin to understand how these types of aggression develop and evolve.
The human body is a complex environment of intertwining systems and pathways. Perhaps the most crucial element of your internal functions is the brain. This convoluted mass of neurons and matter control everything we do: pumping our heart, allowing us to breathe, and sending signals throughout our body to move. But the brain also helps to define us, as some of its compositional regions define our personality, store our memories, and regulate how we think. Naturally, the brain has been examined in innumerable studies for this very reason. What in the brain makes us different from another? Are all our brains different? More specifically, we will be delving deeper into the questions of: what aspects of the brain define a criminal? Are killers’ brains wired differently? And is evil pre-coded into our systems before we are even born?
The brain consists of four main sections, known as lobes, and within these lobes are various regions. To begin, we will first explore the frontal lobe of the brain. This region is responsible for much of our higher thinking, thought processes, and decision making. It is therefore a crucial component in finding an explanation for what makes a criminal, especially since criminals often lack appropriate decision making and problem solving, as reflected in their crimes. Two regions of the frontal lobe must be highlighted in order to understand the regulation of human behavior, the origin of aggression/violence, and how we make decisions.
The first of these regions is the ventromedial prefrontal cortex. This sector of the brain has a wide scope of functions; according to Nicole M. Gage and Bernard J. Baars, writers of Fundamentals of Cognitive Neuroscience (2018), “Roy, Shohamy, and Wager (2012) proposed that the vmPFC [ventromedial prefrontal cortex] is an integrative hub for emotional, sensory, social, memory, and self-related information processing. Situated in the medial portion of the prefrontal cortex, the highly interconnected vmPFC serves as a region for binding together the large-scale networks that subserve emotional processing, decision-making, memory, self-perception, and social cognition in general.” Also functioning in decision-making is the orbitofrontal cortex. Together, abnormalities or damage to these structures have been linked with aggressive and violent behavior (Reddy et al.). Jayasankara Reddy, Karishma Rajan Menon, and Unnati Hunjan summarize these findings in the International Journal of Criminal Justice Sciences, as “An impairment in these structures can lead to impaired decision making, leading to frustration and anger that arises from it (Blair, 2008).”
To gain a full understanding, let’s take a look at some case-studies where criminal-like behavior has been displayed by those with injuries to the ventromedial prefrontal and orbitofrontal cortices.
One such instance is that of Phineas Gage. Studied in many psychology classes, Gage was a railroad worker who suffered extensive damage to his frontal lobe when a pipe struck through his brain. Luckily he survived, but he was not the same man as he was before the accident. Gage underwent a drastic change in personality, becoming significantly more contentious and petulant, and losing much of the responsibility he had prior to the unfortunate event — he was now unable to keep jobs or handle tasks (Reddy et al.).
Similar cases are shown when a tumor is present in these regions of the brain. For example, a man, Michael, with a tumor in his orbitofrontal cortex went from being a loving husband and stepfather to acting in socially unacceptable manners. Not only did he begin to act hostile, but he started to make sexual advances on his stepdaughter and others whom he met. He was a teacher, and pornography was found at the school in his possessions. After brain scans in which the tumor was discovered, it was removed, and Michael’s behavior returned to normal (Reddy et al.).
The ventromedial and orbitofrontal cortex are not the only regions of the brain associated with this violent behavior. Studies have also looked at the anterior cingulate cortex, which is once again located in the brain’s frontal lobe. According to Jayasankara Reddy, Karishma Rajan Menon, and Unnati Hunjan, “Aggression and disinhibition was also found to stem from damage to the anterior cingulate region which plays a role in monitoring conflict, error processing and avoidance learning.” Obviously, these three skills are critical to socially appropriate behavior, as one needs to be able to understand when conflict is arising, recognize when they have done something wrong, and learn from their mistakes to fix their behaviors. Without these thought processes, it would be easy to imagine how someone could act in a criminal manner.
Further exploring the anterior cingulate cortex, psychologist Kent Kiehl of the University of Mexico conducted a study that took a deeper look into this region. Using a functional MRI (an fMRI), Kiehl “looked at the brains of nearly 100 adult male inmates while they completed a task involving inhibitory control. They found that prisoners with lower ACC [anterior cingulate cortex] activity were twice as likely to reoffend four years after they left prison than prisoners with higher ACC activity (PNAS, 2013)” (Miller). As mentioned, the anterior cingulate cortex is responsible for recognizing conflict, error-processing, and learning to avoid behaviors. The results of Dr. Kent Kiehl’s research support these claims, as prisoners with a lower functioning ACC, and therefore lacking the three skills mentioned, engage in criminal behavior repeatedly.
The amygdala is yet another region of the brain believed to be linked to criminal behavior, and plays roles in fear regulation and response, aggression, and social interaction behavior (Miller).
Dr. Dustin Pardini of the University of Pittsburgh explored these ideas by conducting a study that examined the effects of the amygdala on violent behavior. In Padini’s study, “his team found that 26-year-old men with lower amygdala volumes were more than three times more likely to be aggressive, violent, and to show psychopathic traits three years later than men of the same age with more normal-sized amygdales — independent of factors including history of violence and social background (Biological Psychiatry, 2013)” (Miller).
Doctor of philosophy at the department of criminology at the University of Pennsylvania, Adrian Raine, alongside Dr. Yu Gao of CUNY-Brooklyn conducted research into the amygdala’s role in criminality, narrowing focus into the region’s role in fear response and regulation. The researchers sought to analyze fear conditioning in a group of 1,795 3-year-olds. Raine and Gao, “put electrodes on the children’s fingers while repeatedly playing two tones: one that was followed by a loud, unpleasant sound and another that was played alone. Subsequently, the difference in sweat responses to each tone by itself yielded a measure of each toddler’s fear conditioning” (Miller). Two decades after conducting this study, Raine and Gao categorized the participants that had grown to commit crimes and compared them with the participants who had not displayed any sort of criminal behavior; the results: the children that had later in life gone on to commit crimes had failed to demonstrate even minimal fear conditioning. In other words, they did not feel fear as most of us would (Miller). While the participants who had never displayed criminal behavior were scared by the tone followed by the loud and unpleasant noise, the group that had gone on to display violence and criminal actions did not experience this same fear response (Miller).
The above studies and findings make it clear that structural differences in the brain can cause increased aggression and criminal behavior. But what about the components of our neurological functioning that are not visible in an MRI scan? These components are actually our body’s tiny messengers, allowing the parts of our brain and nervous system to communicate rapidly and efficiently. Who are these messengers you may ask?
…Neurotransmitters. The neurological system of our bodies is home to several different types of neurotransmitters, each with its own specific functioning. In this piece, we will look closely at serotonin and dopamine.
Serotonin plays an important role in mood control, and functions in the anterior cingulate cortex within the prefrontal cortex (where the ventromedial and orbitofrontal cortices are located). As discussed earlier, damage to these regions has been linked to increased violence through various studies and research. Any injury or change to these areas directly impacts the serotonin levels by lowering serotonin functioning. These lower levels of serotonin are correlated with an increase in aggression. This idea is further discussed by Jayasankara Reddy, Karishma Rajan Menon, and Unnati Hunjan, as their work found that “Low levels of serotonin in the cerebrospinal fluid are characteristic of a person who is impulsive and aggressive (Glenn & Raine, 2014). The functioning of the orbitofrontal cortex is also reduced when the levels of serotonin fall in the brain and impairment in this region is observed in people with antisocial behaviour patterns (Rubia et al., 2005).” As serotonergic functioning is inhibited, whether by drugs or damage, the regions in which serotonin concentration is high are also affected, and these effects culminate into aggressive and often criminal behaviors.
The second key neurotransmitter corresponding to these behaviors is dopamine, whose primary functions consist of motor movement, alertness, and emotion. Dopamine is also involved in our feelings of motivation and the processing of rewards (Reddy et. al). According to Reddy and his colleagues, an increase in dopamine leads to a decrease in emotional regulation and higher impulsivity, both of which can easily lead to aggression or violence.
In their piece, “Neurobiological Aspects of Violent and Criminal Behavior: Deficits in Frontal Lobe Function and Neurotransmitters”, Reddy, Menon, and Hunjan explore the relation between serotonin and dopamine. Their findings indicate, “an impairment in the functioning of serotonin system and deficiencies in it may lead to an increased activity of the dopamine system and thus leading to impulsivity and aggression.” There are minimal studies conducted on humans to support this matter, however, various studies on animals report these findings; it is likely serotonin and dopamine systems rely on each other, and therefore collaborate in creating criminal behavior.
We have delved into the depths of the human brain, understanding its components that may lead a person to act out in an aggressive, violent, and/or criminal manner. But as we discussed earlier, not all crime and violence are the same.
Throughout my research, I sought to find out what makes a criminal. I encountered many different types of crimes, some more disturbing than others. But none both fascinated and horrified me more than the crimes committed by serial killers. Often, these serial killers are actually psychopathic serial killers.
Psychopathy is rare, according to “research that suggests 1 in 100 people are psychopaths who tend to blend in” (Egan). But the prominence of psychopathy in prisons is much higher, with 15–20% of the prison population being psychopaths (Egan). And while psychopathy does not occur in the majority of criminals, the crimes committed by psychopathic individuals account for 50% of the violent crimes committed each year (Bozzay et al.).
To break this term down, a serial killer, according to the FBI, is “the unlawful killing of two or more victims in separate events” (Marono et al.). However, we will discuss further that a serial killer is often much more than just this definition. “Psychopathy” is defined in the Diagnostic and Statistical Manual of Mental Disorders (the DSM-5, the standard tool used to diagnose mental illnesses and disorders) as antisocial personality disorder (Egan). However, this is not to say that every person with antisocial personality disorder is a psychopath. Psychopaths display a host of characteristic traits and behavioral abnormalities, which are used in their diagnosis.
These characteristic behaviors and personality traits are listed in the PCL-R, the Psychopathy Check-List Revised, created by renowned psychologist Robert Hare. Hare’s checklist consists of 20 items widely used to communicate what psychopathy is in a common language for use by psychologists, since each psychopath is different and may display slightly different behaviors (Egan).
Here are just a few traits that make up the PCL-R: superficial charm, manipulative, impulsivity, lack of remorse, callousness, parasitic lifestyle, and early behavioral problems.
Many of these demeanors and attributes correlate to the characteristics previously evaluated in the research regarding the different parts of the brain. In fact, a study conducted at a medium-security prison in Wisconsin revealed that the brains of psychopaths are different in structure and function.
The study, conducted by a team consisting of Professor Joseph Newman of the University of Wisconsin-Madison, Dr. Kent Kiehl of the University of New Mexico, Michael Koenigs of the University of Wisconsin, and graduate student Julian Motzkin, compared the brains of 40 prisoners. Half were diagnosed psychopaths, while the other half had committed similar crimes but were not labelled psychopaths. The team collected two types of brain scans: a diffusion tensor image (DTI) and functional MRI (fMRI). The DTI measures the organization of the brain’s white matter, while the fMRI displays the activity level of and between different regions of the brain (“Psychopaths’ Brains Show Differences in Structure and Function”).
From the scans taken of the 40 prisoners, the team discovered “psychopaths have reduced connections between the ventromedial prefrontal cortex (vmPFC), the part of the brain responsible for sentiments such as empathy and guilt, and the amygdala, which mediates fear and anxiety” (“Psychopaths’ Brains Show Differences in Structure and Function”).
As discussed earlier, damage or injury to the ventromedial prefrontal cortex often leads to violent behavior, and a low functioning amygdala leads to a lack of fear response. The research performed at the prison in Wisconsin supports these statements; although psychopaths do not have damage to either the ventromedial prefrontal cortex or amygdala, their brain scans show limited neural connections and activity between these two regions, and the result is criminal and violent behavior.
Yet, biological sources of aggression and violence are not enough to drive someone to commit multiple, often heinous, murders the way in which psychopathic serial killers do. To escalate to this level of crime, external sources are often at play.
In serial killers, it is easily noticed that a pattern begins to emerge. Although their crimes may not all be the same, the majority of these killers experienced abuse or trauma during or throughout their childhood.
Many psychologists and writers who study psychoanalysis believe the relationships made early on in an infant/child’s life are key to how they show aggression and violence (Yakeley). Glasser, whose theories of self-preservative and sadomasochistic violence were discussed earlier, also theorized the concept of a “core complex.” Glasser’s core complex, “refers to a particular unconscious constellation of interrelated feelings, ideas and attitudes, a major component of which is a deep-seated and pervasive longing for an intense and intimate closeness to another person” (Yakeley). If a child is not able to achieve this closeness with the mother because of neglect, abandonment, or abuse, then Glasser proposed that the individual is trapped in a cycle of “emotional isolation, rejection and abandonment, which prompt the desire for contact and union with the object again” (Yakeley). This continuous cycle of seeking support and being denied causes the child to resort to violence.
Glasser’s work above is centered around the process of attachment, in which infants fully trust and depend on a specific caregiver, such as a mother or father or both. While Glasser discusses more closely an infant’s relationship with a mother figure, “many individuals…have histories of absent or emotionally unavailable fathers, or abusive fathers who did not provide any source of love or care that the child could trust” (Yakeley).
A child’s experiences of neglect, loss, and abuse “have an impact on the attachment process by interfering with the normal development of affect recognition and expression, empathy and impulse control. In these circumstances, the child resorts to violence as an angry protest” (Yakeley). These same characteristics are also those displayed by serial killers.
Child abuse is defined by the World Health Organization as, “all forms of physical and/or emotional ill-treatment, sexual abuse, neglect or negligent treatment or commercial or other exploitation, resulting in actual or potential harm to the child (World Health Organization, 1999, pg.80)” (Marono et al.). To break this definition down further:
“Physical child abuse relates to acts that cause actual physical harm or have the potential for harm. Sexual abuse is defined as those acts in which a child is used for sexual gratification. Psychological abuse includes the lack of an appropriate and supportive environment or acts that have an adverse effect on the emotional health and development of a child” (Marono et al.). Of these types of abuses, 50% of serial killers say to have suffered psychological abuse, 36% experienced physical abuse, and 26% suggest they endured sexual abuse (Marono et al.).
To understand how childhood experiences lead to the violence carried out by serial killers, Abbie Marono of the University of Lincoln, Sasha Reid of the University of Toronto, David Keatley of Murdoch University, and Enzo Yaksic of Northeastern University began a research inquiry utilizing the Behavior Sequence Analysis (BSA) technique. This method, “investigates how chains of behaviours and events are linked overtime” (Marono et al.).
The team sampled 233 male serial killers who were known to have experienced childhood trauma. Of this sample, 35 participants experienced psychological abuse, 36 underwent physical abuse, 21 suffered sexual abuse, 88 experienced both psychological and physical abuse, 7 said to have dealt with physical and sexual abuse, and 46 participants experienced all three types of abuse throughout their childhood (Marono at el.). The team compared this information with the types of kills each participant went on to commit later in life.
Those who had suffered physical abuse were likely to commit rape/lust murders, in which the murders involved sexual elements. Many of the participants who had experienced physical abuse growing up also displayed overkill on their victim, in which the offender continues to mutilate/damage the body of the victim after the damage has already killed the victim. Serial killers who had experienced psychological abuse were also likely to commit rape/lust killings. According to Marono and her colleagues, “There was also a strong link between torture and evidence of overkill.” While psychological and physical abuse sufferers were likely to commit one of the four murder typologies, those who has endured sexual abuse were linked to all typologies: rape/lust, power, financial gain, and anger kills. Furthermore, participants in the study who had experienced all three types of abuse at a young age were also most commonly linked to commit rape/lust killings.
From the results of this study, it can be seen that the abuse experienced by a child who later went on to kill often plays a crucial role in why and how they kill. Is it possible that if they had not experienced these traumas that they would not have gone on to become serial killers? The answer to this is still not known, but it is clear that early childhood experiences influence these killer’s criminal actions.
To get a holistic view of how the abuses and traumas experienced by individuals with psychopathy can prompt them towards criminal acts, and in this case murders, we will look at the case of Ed Kemper. Kemper was raised in a dysfunctional family, with his mother and father constantly fighting before eventually separating. As a child, Ed displayed a range of disturbing characteristics, such as “the dismemberment of two family cats and playing death-ritual games with his older sister” (Douglas et al.). In many cases, behavior such as this is seen as a warning for future killings, as cruelty to animals is one part of the homicidal triad (which also includes bed-wetting and arsen) that are a commonality in the childhood of serial killers. After Kemper displayed this behavior, his mother sent the young boy to live with his father. He ran away back to his mother, to which she responded by sending him to his grandparents. In Kemper’s relationship with his mother, it can be seen that he was clearly unwanted. The neglect from his mother would eventually lead Kemper to begin his killings, starting with the shooting and stabbing of his grandmother when he was fifteen. After spending time at the Atascadero State Hospital for the criminally insane, he was let out in 1969. In 1972, he killed again. And then again. And then again. (Douglas et al.). Why all these killings you may ask?
The answer: Kemper’s mother. According to FBI profiler John Douglas, “the entire progress of Kemper’s career as a killer can be seen as an attempt to get back at dear old Mom.” Kemper killed at least 6 others, as well as mutilated their bodies after death, before he had the courage to kill his real target, his mother. (Douglas et al.). The neglect and abandonment Ed Kemper experienced as a young boy led him to a deep hatred of his mother, and unfortunately, it drove him to kill.
Kemper’s case shows how one’s environmental experiences can contribute to violence. Did he too have a different brain structure and differing brain chemistry? Much research and copious studies indicate that the answer is most likely yes.
As we have discussed, many psychopathic individuals who develop into serial killers have different brain structure in the regions of the ventromedial and orbitofrontal cortices, the anterior cingulate cortex, and the amygdala. These regions, coupled with the roles of serotonin and dopamine, can all predispose someone to aggression and violence. Combine this with severe abuse at a young age, and it is possible a serial killer has evolved.
References:
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“Psychopaths’ Brains Show Differences in Structure and Function.” UW School of Medicine and Public Health, www.med.wisc.edu/news-and-events/2011/november/psychopaths-brains-differences-structure-function/.
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