There are plenty of ways to diagnose psychopathy in adults — but are there any signs someone might grow up to be a psychopath that are visible before they’ve actually reached adulthood? (Besides, y'know, being the Antichrist like Damien from The Omen here.) Although we don’t generally diagnose children with psychopathy — it’s considered to be an adult disorder — it turns out that there is a certain marker that some children demonstrate which might be linked to whether or not someone develops psychopathy as an adult, according to recent research. It centers around one common social behavior: Whether or not someone finds laughter to be contagious.
The study was originally published in September, but it’s making the rounds again thanks to Indy 100, so let’s take a look, shall we? Conducted by researchers from University College London in the UK, the University of Porto in Portugal, and KU Leuven in Belgium and published in the journal Current Biology, the study examined 62 boys between the ages of 11 and 16 years old who demonstrated “disruptive” behavior, some of whom exhibited callous-unemotional traits — which can be indicative of a greater risk of developing psychopathy later on in life — and 31 boys of the same age who did not demonstrate disruptive behavior. The goal was to see whether the boys with both disruptive behavior and callous-unemotional traits responded differently to laughter that typically developing boys did.
Research supports the idea that laughter is contagious; indeed, a study published in 1992 found that just hearing the sound of laughter generated by a “laugh box” — a “small mechanical record player” which produced canned laughter when activated by participants — was enough to prompt laughter in the study’s participants. Additionally, laughter plays an important social function; according to a 2014 study, it’s often “associated with bonding, agreement, affection, and emotional regulation.” The point is this: Humans not only typically laugh when we hear others laugh; we also laugh with others when they laugh in order to build relationships with them.
Given that psychopathy is characterized by “atypical emotional responses and antisocial behaviors,” including “a reduced empathetic response,”according to the book Neuroimaging Personality, Social Cognition, and Character, it’s perhaps unsurprising that a reduction in laughter contagion might be indicative of psychopathy as well. Indeed, as the current study authors note, “Individuals with psychopathy show a reduced capacity to develop social relationships founded on an enjoyment of prosocial interaction or concern for others’ well-being” — and laughter is a big part of all of that. Accordingly, the researchers hypothesized that boys with disruptive behavior wouldn’t respond as much to laughter at both the neural and behavioral levels; that this would be especially true for boys with high levels of callous-unemotional traits; and that the neural responses to laughter would explain why some of the boys would feel like joining in with it, while others would not.
The boys’ brains were scanned while they listened to a variety of sounds; all in all, the sounds the boys listened to included 30 instances of genuine laughter, 30 instances of posed laughter, 10 instances of crying, and five instances of rest or silence. After the listening and scanning task was complete, the boys were asked to rate the sounds on a scale of one to seven on contagion — that is, “whether listening to the sound made them feel like joining in and/or feeling the emotion” — and authenticity — or, “whether they thought that the sounds were real or posed/faked.”
All of the boys’ brains showed at least some kind of activity when they listened to sounds of genuine laughter — but not all of the boys had the same behavioral response to the stimulus. The researchers found that boys who both displayed disruptive behavior and demonstrated high levels of callous-unemotional traits were much less likely to report wanting to join in with the laughter. Additionally, these boys showed reduced brain activity in two particular regions of the brain — the anterior insula and supplementary motor area — that are associated with empathizing and joining in with others’ emotions. All of this seems to indicate that boys who display other traits consistent with developing psychopathy as an adult don't find laughter nearly as contagious as typically developing boys do.
There are, however, a lot of caveats to the study’s results: First off, it only focused on boys, so the results might not hold true for other genders; second, correlation is not causation (that is, not only does psychopathy not necessarily cause a lack of laughter contagion or vice versa, additionally, if you don’t find laughter contagious, that doesn’t necessarily mean you’re a psychopath); and third, “psychopath” isn’t a diagnosis that we generally give to children. Said senior study author Essi Viding according to Science Daily, “It is not appropriate to label children psychopaths. Psychopathy is an adult disorder.” The point of the current study was to examine markers that have been observed in other, longitudinal studies that indicated kids were at a higher risk of developing psychopathy; the researchers “screened for those features that indicate that risk,” according to Viding.
However, even owing for these caveats, the study offers a lot of paths worth exploring in future research. Wrote the study authors, “This study highlights the need for systematic longitudinal research to investigate the causal relationship between atypical responses to affiliative social cues and psychopathy. Such research would make it possible to explore the directionality of effects in different groups of children with disruptive behaviors and the degree to which these processes are under reciprocal influence.” If we’re able to pin down certain behaviors that predict psychopathy, we might be able to develop methods of prevention and intervention that help mitigate the effects of the disorder — that is, we might be able to develop treatments that will “promote the formation of affiliative bonds and reduce the risk of antisocial behavior,” as the study authors put it.
And that could have a wide-reaching and positive effect, indeed.