Skip to main content

Verified by Psychology Today


Are Serial Killers Born or Made?

Perhaps they are natural born potential killers.

Natural-born killers?

On November 13, 2020, Peter Sutcliffe died unmourned in the University Hospital of North Durham after refusing treatment for Covid-19. Known as the Yorkshire Ripper, Sutcliffe was convicted of the murder of 13 women and the attempted murder of seven others between 1975-1980. At no time did Sutcliffe appear to show any remorse for what he had done.

What made Sutcliffe and others like him the people they became? Ted Bundy (30 murders confirmed) Pedro Rodrigues Filho (70 murders confirmed) Luis Garavito (138 murders of street children confirmed). Were they natural-born killers all along, or did something change them and make them into serial killers?

Neuroscientist Jim Fallon had few doubts. Psychopathic killers were born, and he believed he was beginning to find the evidence to prove it.

It wasn’t me; it was my brain.

Lawyers had been sending Fallon brain scans of convicted murderers in the hope that he could show there was something wrong with their brains that would perhaps get them a lighter sentence, or maybe help them escape the death penalty. After several years, Fallon was beginning to see a pattern.

To test his ideas objectively, he set up a blind trial. Colleagues sent him 70 brain scans: some were of people with a diagnosis, such as schizophrenia or depression, some were from people with no diagnosis and some were from convicted killers.

Fallon successfully identified all the ‘killer brains’ in the sample.

‘They all had one thing in common,' says Fallon, 'a loss of function in the orbital cortex, above the eyes, which is the circuit that codes for ethics, morality, conscience and when that’s gone, or doesn’t develop, not only does a person have no sense of morality but also has little control over their impulses.’

But Jim Fallon was in for an unpleasant surprise.

Me too?

Fallon had arranged PET brain scans for ten members of his own family as controls for a project he was conducting on vulnerability to Alzheimer’s disease. Looking through these scans one October afternoon, he was shocked to find one that looked just like, in his words, ‘the worst serial killer brain’. When he broke the code, he found he was looking at a scan of his own brain.

‘I get the joke,’ smiles Fallon. ‘You know, I'm studying serial killers and I've got a brain that looks just like one. You can't make this stuff up. The real things that happen in your life are often quite strange.’

There was more to come. Fallon had also had his family's DNA examined as part of the Alzheimer's project. When he checked them, he found they had normal, balanced combinations. Except for one.

‘One had all of these markers that were really high risk for violence,’ says Fallon. ‘And, of course, it turned out to be me again. Now, it became a bit more serious, because I had both the brain pattern and the genetics that were very consistent with a really bad news killer, a psychopath really.’

If Fallon’s research was right, and he was sure it was, then how come he wasn't a killer, a Peter Sutcliffe, a Ted Bundy, or a Luis Garavito? It suggested that while brain abnormality and genes linked with aggression and violence were necessary causes of psychopathic aggression, they weren’t sufficient. There had to be something else. And for Fallon, this ‘something else’ may come from childhood.

Fallon’s belief that his happy and secure childhood may have protected him from ‘a bad throw of the genetic dice’ and led him re-think some of his long-held ideas. Maybe neuroscience didn't have all the answers after all?

‘To all my colleagues I was like Mr. Genes,’ says Fallon, ‘genetics control everything. But it was like the joke’s on me. I had to say I was wrong. And so that was really a very enlightening thing. And because I was wrong, I really had to study it more. How was I wrong? And you know I got a fix on that.’

The unholy trinity

For Fallon, there are three necessary ingredients that, when they come together, can produce psychopathic killers.

The first is a loss of function in the orbital cortex which can leave people incapable of ethical decision-making and also makes them less able to control their impulses.

The second is inheriting genes, such as the MAOA gene, that predispose a person to aggression and violence.

And the third, having a childhood devoid of love, affection, and care that fails to protect people from their latent psychopathology. Peter Sutcliffe, Ted Bundy, Pedro Rodrigues Filho, and Luis Garavito all had troubled or abusive childhoods.

We began by asking whether there really are natural-born killers. Well, it seems the answer is yes and no. Better to say that there are natural-born potential killers.

Whether that awful potential is realised would seem to depend on environmental influences and, in particular, the love given, or denied, in early childhood.

Facebook image: DedMityay/Shutterstock


J. Fallon (2013) The Psychopath Inside. Penguin Putnam

Jim Fallon: Natural Born Killer?

More from Steven Taylor Ph.D.
More from Psychology Today