Recipe for a serial killer?

You must agree that ‘Recipe for a Serial Killer?‘ is an attention grabbing headline! In the first of our How to “Research the Headlines” posts, we spoke about the use of OTT headlines to ensure the reader chooses to read the story attached to the headline.  So let’s see if current coverage in the media about the risk factors for becoming a serial killer has revealed the ‘recipe for a serial killer’.

Who were the researchers and what type of study was this? 

The study was conducted by a research team based at the Institute of Health and Wellbeing at the University of Glasgow (the first named author of the paper is Clare Allely and the corresponding author is Helen Minnis) and collaborators  based at the University of Aberdeen and the University of Gothenberg.  The paper that reports the findings was published in the Journal ‘Aggression and Violent Behaviour’ and is what is referred to as a ‘systematic review’ which is basically a thorough review of studies on a specific topic. Such a paper therefore brings together a range of previous study findings rather than reporting new findings. This paper was also published as ”Open Access’, an increasingly common trend for journal articles, which means it is accessible to all and does not require a subscription to a particular journal or library. The general public can just Google the article name (or click on ‘paper’ highlighted a few sentences above!) and voila, it is there to read.

So what did the researchers do?

The researchers used a series of search terms such as autis (to enable a search for autism and autistic), brain injury, violent crime and mass killing to examine the factors underlying serial killing. Autism and brain injury were examined because they have previously been implicated in research in the area. Because the literature available on this topic was limited, the researchers looked to newspaper articles, court transcripts and online articles in addition to the more traditional focus in systematic reviews on academic journal articles and chapters. This of course limits the scientific credibility of the findings.

What did the researchers find?

Among all of the 239 eligible killers identified, 28% had ‘definite, highly probable or possible’ autistic spectrum disorder (ASD) of which 7% also had a head injury. 21% had had a definite or suspected head injury of which almost 14% also had evidence of ASD traits. Out of the 106 killers with ASD and/or head injury, 55% had experienced psychosocial stressors (e.g. parental divorce or abuse). These findings suggested that it is the interplay between factors such as autism/head injury and early adverse life events that heighten the risk for violent behaviour rather than any factor being important in its own right.

How did the media handle reporting of the findings? 

The media generally reported the figure that 28% of the serial killers had autism without using the researchers wording of ‘definite, highly probable or possible autism’. The researchers themselves note the limitation of their review in relying on non-peer reviewed sources such as newspaper articles and online resources whereby determining that a serial killer met actual diagnostic criteria for ASD would be very difficult in most cases. The media did well to refer to the researchers’ concern that having ASD or a head injury in isolation were not a risk factor for psychopathic tendencies. Importantly, the Daily Mail and the Independent coverage also included independent expert opinion from the National Autistic Society, which we have highlighted before as important for balanced reporting. This expert, Carol Povey, echoed the researchers’ concerns about not jumping to conclusions about people with autism. She said that ‘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”. In general then the reporting was very sensible about this research although the headline may have been overegging it a little!