Nature vs. Nurture in the Making of Serial Killers

Neurodevelopmental Risk Factors in Serial and Mass Killers

Allely, C., Minnis, H., Thompson, L., Wilson, P., & Gillberg, C. (2014). Neurodevelopmental and psychosocial risk factors in serial killers and mass murderers. Aggression and Violent Behavior, 19(3), 288–301.

The researchers in this study conduct a meta-analysis of relevant literature — including academic studies and legal sources — in order to assess the "complex interaction of biological, psychological, and sociological factors" that contribute to the making of a serial killer (p. 288). What the study finds is that a "significant proportion of mass or serial killers have had neurodevelopmental disorders such as autism spectrum disorder or head injury" (p. 288). This finding indicates that nature plays a distinct role in the motivation of serial killers.

However, it is important to note that correlation does not equate to causation, and the study merely depicts a correlation between autism spectrum disorder and serial killing: it does not assert that the former causes the latter, only that it is a common theme. For example, the study notes that out of 239 serial killers analyzed, 28% "had definite, highly probable or possible" autism spectrum disorder. Roughly 20% of the same sample had suffered a head injury. Thus, the researchers conclude that there is a correlation between a negatively impacted biology and the development of serial killers.

The study calls for further investigation into this correlation and is significant because it draws attention to head trauma and biological dysfunction as contributing factors in the serial killer's natural motivation. For this reason, the study makes a supportable claim for the nature side of the debate over whether it is nature or nurture that leads serial killers to act.

The MAOA Gene: Nature and Nurture in the Criminal Mind

Highsmith, J., Mercado, M., Hernandez, J., & Madrigal, S. (2015). Nature (MAOA) and nurture in a criminal. UC Merced Undergraduate Research Journal, 8(1), 1–10.

Highsmith et al. examine the nature versus nurture question with regard to what shapes the mind of a criminal. They identify articles supporting the notion that nature is a significant factor in the make-up of the criminal mind, as numerous researchers have found that "low levels of monoamine oxidase A gene (MAOA) lead to higher rates of aggression" (p. 1). The researchers also use the example of Ted Bundy as a serial killer who came from a normal, healthy, loving family but who had low levels of MAOA and thus carried a higher risk of deviating toward aggressive behavior.

That, however, is not the complete story. The researchers also indicate that nurture plays a part in the development of a serial killer like Ted Bundy. It is not merely the effect of a genetic predisposition that motivates the killer but rather a series of compounding factors that gradually push the killer in that direction.

The study is significant because it addresses head-on the question of nature versus nurture and the serial killer's criminal mind. It shows that there is no easy answer to the question and that both angles must be considered deeply in order to produce a coherent picture of why serial killers act. According to this study, the best way to answer the question is to acknowledge that both nature and nurture play a role in the development of the serial killer and that each aspect must be examined more fully on an individual basis, as no two serial killers are exactly alike — each comes from a distinct background and has its own genetic and psychosocial make-up that contributes to the killer's evolution.

Consumer Culture and the Nurturing of the Serial Killer

Jarvis, B. (2007). Monsters Inc.: Serial killers and consumer culture. Crime, Media, Culture, 3(3), 326–344.

This study suggests that serial killers and the culture that surrounds them are nurtured by a need to commodify murder and make it into something tangible that people can possess. This was certainly the case for Jeffrey Dahmer, who wanted to possess his victims and essentially own them — which is why he killed them. With the murderabilia culture, this cycle of ownership is perpetuated and nurtures the sentiment that drives serial killing. Jarvis tracks the sale of murderabilia and the depiction of serial killings in popular films and television — including Saw, American Psycho, CSI, Law & Order, and A Nightmare on Elm Street — to show how a culture of death permeates modern society. It is this culture, he argues, that nurtures the serial killer and allows him to grow into the killer he becomes. If society were not so dominated by a consumerist impulse, the motive of the serial killer would not be so strong — which is clearly evident in the case of Dahmer, whose entire world was disoriented by a dismal home life that placed materialism above deep human connection.

Jarvis's overall point is that consumerism is a violent, materialistic ideology, and it is therefore unsurprising that it should be consumed by an obsession with violence. Art acts as a mirror, and audiences have always loved to see themselves represented on stage. The depiction of grisly violence reflects a consumerist culture's thirst for violence as well as its acceptance of and pleasure in horror and blood. Jarvis's claim is that consumerism is an appetite that demands the death of something else in order to be momentarily filled, and that such an appetite is inherently related to the murderous impulse of the serial killer. Thus, the serial killer is essentially nurtured into being by a culture of death in American society.