A neuroscientist has concluded that Jeffrey Dahmer was not a psychopath - claiming that he 'doesn't fit the mold'.
Professor James Fallon, 74, a neuroscientist at the University of California, made the shocking revelation in the wake of Netflix's Monster: The Jeffrey Dahmer Story, which covers the killer's horrific crimes.
He said that psychopathy is characterised by a lack of empathy for other people, while claiming that Dahmer experienced 'emotional empathy'.
Psychopaths are also said to have other characteristics such as manipulative tendencies, a lack of remorse, and a lack of respect for societal norms and the law.
Instead, Professor Fallon said that the killer, who took the lives of 17 men and boys, was suffering from borderline personality disorder (BPD).
This is a condition characterised by emotional instability and poor impulse control, per the NHS - which Professor Fallon believes are qualities that characterised Dahmer's story.
But he is now warning true crime fans that psychopath shouldn't be used as a generic term to describe bad people, as he claims it is a lot more complex than that.
"Jeffrey Dahmer was not a psychopath. His characteristics all point to BPD," he said.
"It was never confirmed he was a psychopath but everyone assumed for simplicity's sake that a bad person is a psychopath.
"He showed emotional empathy with people and many psychopaths don't have that."
Another symptom often characterised with BPD is a fear of abandonment, which Dr Fallon believed to be why Dahmer claimed to have killed many of his victims.
The professor said: "A common thing with people with BPD is that they have these crazy fears of being abandoned.
"Jeffrey Dahmer seemed to fear this all the time - when the men he met tried to leave him, he would kill them so they couldn't."
Professor Fallon also claimed that this motivated Dahmer's cannibalism, in order to ensure that his victims 'can't leave'.
He said: "A lot of people feel this with babies or puppies, like 'I love this baby so much that I want to eat it' - that's actually an impulsive take on an otherwise normal way of thinking about ingesting someone.
"Dahmer took it to extremes because he needed that feeling that the person would always be with him and he'd never be abandoned."
People with BPD also tend to engage in risky behaviours, both sexually and otherwise, which led Professor Fallon to believe that Dahmer had 'extreme BPD'. He also noted other examples of 'self-destructive behaviour' like 'putting himself in risky situations that could have endangered him'.
However, he did also stress that because we have no access to brain scans of Dahmer or his genetics (he was cremated after being murdered by another inmate in 1994), so we will never know absolutely if he had BPD or was a psychopath.
He said: "When you think of the famous serial killers, Dahmer included, everyone loves to think for simplicity's sake that they're all the same.
"It's never been fully confirmed Dahmer was a psychopath but it does keep coming up.
"But his characteristics don't agree and I don't believe he was.
"We'll never know for sure because we can't see his genetics or brain images, but I feel he was more like someone with BPD."
If you're experiencing distressing thoughts and feelings, the Campaign Against Living Miserably (CALM) is there to support you. They're open from 5pm–midnight, 365 days a year. Their national number is 0800 58 58 58 and they also have a webchat service if you're not comfortable talking on the phone