Recipe for a serial killer? Childhood abuse, autism and head injuries are more common in murderers, study claims



Researchers studied journals, new stories and legal files for murder cases

They found that 28 per cent of murderers were thought to have suffered from Autism Spectrum Disorder (ASD)

21% had suffered a ‘definite or suspected’ head injury in the past

And of those killers with ASD and head injury, more than half had previously experienced psychosocial stress

But researchers stressed that having ASD or a head injury alone were not linked to psychopathic tendencies

Instead, small subgroup of these people suffering with a combination of problems would be more likely to kill



Psychosocial stress includes exposure to sexual abuse during childhood

Serial killers are portrayed as cold, calculating and often obsessive but it was unknown exactly what caused them to commit such heinous crimes.



Now research from Glasgow has found that these similar traits among different murderers may be linked to specific psychological disorders and childhood trauma.



Researchers from Glasgow have conducted the first ever analysis of journals, news reports and legal files involved in the cases of killers, including Anders Breivik and Dr Harold Shipman.

They discovered a link between suffering a combination of Autism Spectrum Disorder (ASD), a head injury and a psychosocial disorder, such as that caused by exposure to abuse in childhood or parental divorce.

The study found 28% of killers were thought to have suffered from Autism Spectrum Disorder (ASD), and a fifth suffered a 'definite or suspected' head injury. This venn diagram shows the proportion and overlaps between head injury and/or ASD and psychosocial stressors

Breivik was convicted of mass murder in 2012 for causing a fatal explosion and terrorism in Norway in 2011. During his attack eight people died in the bombing and 69 more died in a mass shooting.



In January 2000, a jury found Dr Harold Shipman guilty of killing 15 of his patients - although he is believed to have been involved in the death of up to 250.



Other killers studied included 1996 Australian mass murderer Martin Bryant, and 2008 Exeter nail bomber Nick Reilly.



THE METHOD BEHIND THE STUDY

The team from Glasgow searched studies and books that were both published and still in progress which referred to serial killers, violent crime, psychopathy, narcissistic personality disorder, and Autistic Spectrum Disorders. This included Web of Knowledge and PsycINFO, and search terms included ‘autism and serial killer’, ‘psychopathy and autism’, ‘murder and autism’, ‘brain injury and serial killer’, among other relevant searches. Among the 239 eligible killers, 28 per cent had ‘definite, highly probable or possible ASD’ of which 7 per cent also had a head injury. More than 21 per cent had suffered a definite or suspected head injury, of which 13 per cent also had evidence of ASD traits. Out of the 106 killers with ASD and/or head injury, more than half (55 per cent) had experienced psychosocial stressors.



According to the findings, 28 per cent of the high-profile killers were thought to have suffered from ASD.

In contrast, around one in 100 of the general population is thought to suffer from the condition.

There were additional reports that claimed a fifth had suffered a ‘definite or suspected’ head injury in the past.

Of those killers with ASD and/or a head injury, more than half had previously experienced psychosocial stress such as sexual or physical abuse, but also parental divorce.

The Glasgow research, therefore, concluded probably more than 10 per cent of serial killers on the whole, across the worldwide population, show signs of ASD, and a similar proportion have had a head injury.



This combination could potentially result in an individual being predisposed to develop into a mass murderer.



‘The report, which is the first of its kind to look at all the available material around serial and mass killers, identified that a complex interplay between neurodevelopmental problems and psychosocial factors are most likely to lead to incidences of this kind,’ explained the study authors, led by Dr Clare Allely.

But the researchers claim that a person suffering a neurodevelopmental disorder or a brain injury, by itself does not result in a serial killer or mass murderer.

To test the hypothesis, the team from the University of Glasgow searched studies and books that were both published and still in progress that referred to serial killers, violent crime, psychopathy, narcissistic personality disorder, and Autistic Spectrum Disorders.

Researchers from Glasgow analysed journals, news reports and legal files involved with cases of serial killers, including Anders Breivik (pictured). They discovered a link between Autism Spectrum Disorder (ASD) and psychosocial disorders, such as exposure to abuse in childhood or parental divorce, among serial killers

Databases included Web of Knowledge and PsycINFO, and search terms included ‘autism and serial killer’, ‘psychopathy and autism’, ‘murder and autism’, ‘brain injury and serial killer’, among other relevant searches.

The researchers also examined book chapters, whole books and electronic documents available locally, and through the UK’s inter-library loan system.

Among all the 239 eligible killers, 28 per cent had ‘definite, highly probable or possible ASD’ of which seven per cent also had a head injury.

More than 21 per cent had suffered a definite or suspected head injury, of which 13 per cent also had evidence of ASD traits.

Mass murderer Dr Harold Shipman, pictured, was 'highly suspected to have had ASD' and had experienced stressors in the past, the study found

Out of the 106 killers with ASD and/or head injury, more than half (55 per cent) had experienced psychosocial stressors.

The paper added that despite the ‘exhaustive search’ reports on fewer than 400 serial and mass killers were found since 1985, suggesting they are rare.

Dr Allely, from the Institute of Health and Wellbeing at the University of Glasgow, continued: ‘It is crucial to note that we are not trying to suggest individuals with ASD or previous head trauma are more likely to be serial killers or commit serious crime.

‘Rather we are suggesting that there may be a subgroup of individuals within these groups who may be more likely to commit serious crimes when exposed to certain psychosocial stressors.

‘Research on mass and serial killing is still very much in its infancy. New research is urgently required to understand the mechanisms underlying these extreme forms of violence so that preventative strategies can be developed.

‘We would recommend that in future, all serial or mass killers who are apprehended should be thoroughly assessed using standardised tools for investigating neurodevelopmental disorders including ASD and head injury.’

The findings are published in the in the Journal of Violent and Aggressive Behaviour and the full paper can be viewed at Science Direct.

Carol Povey, Director of The National Autistic Society’s Centre for Autism, told MailOnline: 'This is a very serious issue and research like this is vital if we are to develop preventive strategies.

'But we would urge people not to jump to conclusions about people with autism and to make judgements about a whole section of society.

'This and previous research shows that the vast majority of individuals with autism are law abiding and respect the rules of society. Indeed, in many cases, individuals with autism are unusually concerned to keep the letter of the law, due to the nature of the disability.

'This research reaffirms the importance of ensuring that people with autism get the support they need as early as possible.'

