The MacDonald Triad
Another Look at True Crime Lore
John MacDonald’s “The Threat to Kill” paper published in the American Journal of Psychiatry in 1963 has generated far more attention than most academic papers.
Far more.
Somewhat ahead of its time, the study examined family dynamics, family abuse, and early childhood developmental factors as distal predictors of homicide perpetration.
Of these factors, three have gained substantial cultural relevance: bedwetting or enuresis, animal cruelty, and firesetting. The presence of these three, it was theorized, significantly increases the likelihood of lethal violence later in life.
The variables became go-to red flags for murder.
The MacDonald Triad has been part of true crime lore ever since.
Enuresis, animal cruelty, and firesetting became standard variables in many studies of sexual homicide offending, and scarcely an episode of Criminal Minds goes by without mention of these factors.
In the true crime ecosystem, the MacDonald Triad is seemingly essential for explaining homicidal development.
On the other hand, the research community suggests the MacDonald Triad is largely overblown. Several studies found their effects wash out once other risk factors for violence are considered.
Moreover, the three behaviors are usually not found together, but instead appear singularly along with many other risk factors for serious criminal activity.
From a criminological perspective, enuresis, animal cruelty, and firesetting are not the evil triple crown for the development of murder.
To illustrate, my dataset of 636 capital murderers sentenced to death in California, many of whom are serial murderers and/or sexual homicide offenders shows most do not display these warning signs. Of my total sample,
· 4.1% set fires during childhood
· 3.1% harmed animals
· 4.7% displayed enuresis
In addition, behavioral disorders like conduct disorder mediate much of the effects of the MacDonald Triad on subsequent criminal activity. In the California data, for instance, conduct disorder mediates 91% of the effects of the MacDonald Triad on arrest onset.
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Of these risk factors, enuresis is the most complex, and controversial.
Enuresis is urinary incontinence among children who should have the bladder control to avoid wetting their bed. As any parent can attest, bedwetting is a normal part of childhood.
Boys usually have more difficulty with toilet training than girls, and, as such, have more bedwetting problems. And like all behaviors, there is a range for achieving urinary continence.
On the other hand, frequent or prolonged bedwetting could also be indicative of a larger problem. It can be a behavioral indicator of developmental delay or even developmental disorder. Children with pervasive developmental disorders, for instance, sometimes never attain urinary continence when they sleep.
It also can represent parental problems or abuse, which was its focus in the original study. Some children are prevented from getting up at night to use the toilet, a cruel but passive form of emotional abuse imposed by one or both parents. In more severe cases, children are so terrified of the abuses in the home that they wet their bed in fear.
It is a proxy for household trauma.
Firesetting and animal cruelty are more straightforward risk factors although these also reflect a range of behaviors from troubling to pathological. The former encompasses playing with matches and incendiary materials to earnest attempts to use fire to damage property and harm people.
The earliest criminal onset I have seen involved an individual who had arson arrests during adulthood who was contacted by police with matches and gasoline prior to age 3.
For him, there was continuity between his preschool firesetting and adult offending.
Animal cruelty can range from teasing to physically abusing to killing an animal. The notorious contract killer Richard Kuklinski described animal cruelty and abuse as a favorite pastime of his youth, and killed scores of dogs, cats, and other animals.
In extreme cases like this, violence directed toward animals is an early trial run for killing and a way to manifest their homicidal ideation. They want to feel the destruction of life.
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Like most debates, the true value of the MacDonald Triad is somewhere in the middle between the true crime certainty and the academic skepticism.
Like most debates, the true value of the MacDonald Triad is somewhere in the middle between the true crime certainty and the academic skepticism. Any of these features can be a troubling sign of behavioral maladjustment.
In terms of firesetting and animal cruelty, the prognostic value is far greater than a troubling sign. Research with national-level data shows that individuals who have ever engaged in firesetting or animal cruelty are significantly more antisocial than those who have not.
They are also more likely to have the behavioral disorders, such as conduct disorder and antisocial personality disorder, which are endemic to correctional populations.
In this way, firesetting and animal cruelty are not overrated true crime myths; they are empirically validated markers of serious antisociality.
They just do not always occur together in the same person.