1963. Psychiatrist J M Macdonald has his paper “The Threat to Kill” published in the American Journal of Psychiatry. This paper proposes that three factors, or a combination of any two of these factors, present in children or the childhood, could predict that that person could develop tendencies that were violent or predatory behaviour. So this includes, but is not limited to, homicidal tendencies and/or sexually predatory behaviour. So Macdonald argued that if you did two or three things as a kid, you are more likely to commit violent or predatory crimes as an adult.
The triad, sometimes called the triad of sociopathy or the homicidal triad, highlights three behaviours: cruelty to animals, fire-setting or an obsession with fire-setting, and persistent bedwetting.
Macdonald’s study on this triad involved taking data from 48 psychotic patients and 52 non-psychotic patients, all of whom had threatened to kill someone. The participants were roughly equal in terms of male and female, and the ages ranged from 11-83. I will talk about this study in a bit more detail later but I wanted to highlight his theory came from a study he conducted.
Cruelty to animals
There are a number of theories as to why some animal abuse in childhood occurs but realistically there is not one overriding factor.
Some belief it is a coping mechanism to vent frustration against those they cannot harm. Let’s say a child is excessively humiliated by a primary caregiver, they wouldn’t be able to retaliate, so they would seek something that is vulnerable or weak to exert control over or harm – like an animal.
A 2003 piece of research by McClellan noted that out of 45 violent male inmates 56% admitted to animal cruelty in their childhood. Further, those who did undertake acts of abuse against animals were more often the victims of parental abuse than those who didn’t.
Alan Brantly, an FBI special agent, believed that killing animals is sometimes a rehearsal for killing humans and other studies show that those who went on to kill humans, used the same methods for killing both their human and animal victims.
According to Singer and Hensley’s 2004 paper fire-setting or arson is often considered to be one of the first things children do to release aggression. Again, like the first point in cruelty to animals, it is often a coping mechanism for being humiliated.
Bedwetting is common in children but after the age of five persistent unintentional bedwetting during sleep is called enuresis. Whilst the bedwetting itself may not be a cause of any homicidal tendencies in adulthood – we could, again, link this to humiliation. Here it’s a child being humiliated as a result of something they have no control over.
There has clearly been great interest in these topics and as a result there has been a number of studies on it and a number of studies on certain aspects of the factors.
But like anything in social science, there is always a rebuttal. Always an argument. Always a flaw.
Macdonald’s study was just that, flawed. 100 participants isn’t necessarily a terrible sample size and the demographic of that group also wasn’t terrible, but for this kind of subject, it could be argued that this group was too small and not representative of the general population at large.
We have to take into account here that data comes in two forms: quantitative – i.e. quantity based information that is measurable: numbers, percentages, how many units of Jaffa cakes sold in the past two weeks; and qualitative – data coming not in the form of numbers – i.e. stories, case notes, a transcript of a police interview.
Macdonald’s data for his study came from observation in a clinical setting, which is an artificially created environment that could alter the value of any data – and even he recognised that there was no predictive value in his study. Further, and probably more importantly, it is really key note that those included in this initial study hadn’t actually harmed anyone, they had just threatened to.
The triad seems pretty prolific. But how did it gain so much momentum? The 1960s weren’t exactly the cutting edge of behavioural science. Do the names John Douglas, Robert Ressler and Ann Burgess mean anything to you? How about the names of their fictional counterparts – Holden Ford, Bill Tench and Dr Wendy Carr?
That’s right – Douglas, Ressler and Burgess claimed substantial evidence to support the theory of Macdonald and the Macdonald Triad in their work profiling serial killers as part of the FBI’s Behavioural Science Unit for psychological profiling. We know these characters from Mindhunter which was based on a series of real events. (We review season two of Mindhunter in EP5 – Radioactive Rattlesnakes).
Despite evidence to the contrary and flaws in Macdonalds own initial study, that didn’t stop a team of psychiatrists a couple of years later, testing this theory on 84 offenders who were at the time imprisoned. 53 of the offenders were not aggressive, yet 31 were considered to be violent. Out of the violent offenders, it was noted that three quarters of them had one or two of the factors of the triad and 45% of the violent offenders, had all three. But, again, this study is too small and was designed poorly. When the study was replicated with a larger group and tighter controls, it couldn’t produce the same results. In fact, their results didn’t even come close.
The triad is the subject of the 2018 paper by Parfitt & Alleyne called “Not the Sum of Its Parts: A Critical Review of the MacDonald Triad.” They explore the how valid the triad is and conducted their own review of the information available. They make three main conclusions:
- Any one of the factors could predict violent future offending, but it’s very rare to find all three in one subject.
- Evidence of the factors would point to a home environment that could be considered to be dysfunctional or a child having poor coping strategies. This means there could be other factors at play that could account for violent behaviour being exhibited in adulthood.
- Further research on this theory needs to take place with strict, rigorous controls to establish the validity.
Dr Katherine Ramsland, who wrote a really good article on Psychology Today, comes to the conclusion that we should move away from stating outright that evidence of the triad, or two factors the triad, is indicative of someone being a future serial killer. Instead we should look at evidence of the factors indicating a child who may be stressed, that has poor coping mechanisms or developmental disabilities who needs guidance and attention.
Wikipedia argue that childhood experience of parental neglect, brutality or abuse are more likely to affect whether someone is more violent in adulthood than the factors associated with the triad.
We’d love to know your opinion on this fascinating subject.
Parfitt & Alleyne (2018) Not the Sum of Its Parts: A Critical Review of the MacDonald Triad (accessed on 22 December 2019)(available at https://www.ncbi.nlm.nih.gov/pubmed/29631500)
Psychology Today – https://www.psychologytoday.com/gb/blog/shadow-boxing/201203/triad-evil
Wikipedia – https://en.wikipedia.org/wiki/Macdonald_triad