The Uncanny Similarities Between Jeffrey Dahmer And Dennis Nilsen

In his bestselling 2011 book "The Psychopath Test," British journalist and broadcaster Jon Ronson explores the phenomenon of psychopathy through a controversial idea: that a checklist of traits (known as a PCL-R test) alone can be used to work out whether anybody is a psychopath. The hypothesis is highly seductive; the idea that psychopaths live among us — and potentially account for 1% of the population, according to Ronson's research — is terrifying. Equally so is the idea that we, the reader, may coldly lack some key empathetic qualities ourselves (though as a review in the Los Angeles Times points out, such anxiety over our own potential psychology is more likely a good indicator that we are harmlessly sane). Why wouldn't we want to be able to reduce the diagnosis of psychopathy as a label to a reliable yes-or-no checklist?

But most disturbing of all when it comes to psychopaths is that whether it is possible to diagnose them as cleanly as supporters of the PCL-R would have us believe, research suggests that people aren't just born with the mental disorder. While there is evidence that there may exist a genetic disposition to psychopathic behavior (per Business Insider), psychopaths are more than likely made. This dynamic is evidenced by the uncannily similar backgrounds — and crimes — of two of the world's most terrifying serial killers: Jeffrey Dahmer and Dennis Nilsen.

The killers shared similar childhoods

Despite being born and raised on two different continents, serial killers Jeffrey Dahmer (pictured above) and Dennis Nilsen have a lot in common, which becomes especially disturbing in light of their horrendous crimes.

After their arrests, the two killers would reveal the childhood and adolescent traumas that became catalysts for their later psychopathy. According to Biography, the Wisconsin-born Dahmer is believed to have been a good-natured and happy child until the age of four, when, after developing a double hernia, he was subjected to invasive surgery to correct the problem. Per Science Direct, Dahmer likely began to eschew social interaction after this trauma. 

Nilsen, from Scotland, suffered his own trauma at the age of six, when his grandfather, to whom he was particularly close, died unexpectedly. At the funeral, the boy was invited to look upon the body at rest — an experience that deeply affected him (via Biography). 

Both Dahmer and Nilsen were raised within unhappy households under marriages that ended in divorce while they were still adolescents. Elsewhere, the future killers both had stints in the military, and they both had periods of heavy drinking.

The parallel crimes of Dahmer and Nilsen

In another eerie parallel, both Jeffrey Dahmer and Dennis Nilsen (pictured above) began killing in 1978. They each targeted vulnerable young men — lone travelers, homeless men, or drinkers — and lured them to their homes where they brutally murdered them. Dahmer's first victim was a hitchhiker named Steven Hicks, whom he murdered at his parent's house. Afterward, he buried the body before exhuming it and pulverizing the bones (via Biography). Nilsen's first victim was a man he had met in a London pub before strangling him at his home the next morning (via Biography). 

In both cases, the violence occurred after the victim had expressed their intention to leave. It is believed that both killers' psychopathy was related to extreme feelings of abandonment that first developed in their adolescence and subsequently manifested in a perverse sexual attraction to passive bodies — both unconscious and dead. Both killers would go on to murder many more young men for their sexual pleasure — Dahmer killed a total of 17, while Nilsen is believed to have killed between 12 and 15. In addition, both murderers retained the bodies of their victims for long periods before dismembering and disposing of them.

However, the two serial killers differed greatly in their ultimate fates: while Nilsen died in hospital of a pulmonary embolism on May 12, 2018, at the age of 72 (via BBC), Dahmer was beaten to death behind bars by a fellow inmate Christopher Scarver in 1994, aged 34.