Last week I wrote about the DSM-5’s criteria for diagnosing individuals with psychopathy (or ASPD). The key point was that the DSM-5 defined psychopathy in terms of behaviors. Individuals who had (e.g.) repeatedly broken the law and pathologically lied could be diagnosed as psychopaths, without the need for a personality inventory or fMRI scan.
One interesting consequence of defining psychopathy in terms of behavior is that it is at least theoretically possible for non-human animals (or perhaps extraterrestrial beings) to exhibit the requisite behaviors sufficient for a diagnosis. So one might ask, “if a non-human exhibited similar behaviors, would they likewise be a psychopath?”
Robert Latzman et al. recently put forward a triarchic model of psychopathy for chimpanzees that could be used to make such a diagnosis (though, to be clear, making a clinical diagnosis of chimpanzees was not the goal of their research).
Their triarchic model frames psychopathy in terms of three dimensions: disinhibition, meanness, and boldness. A high level of expression of each of these dimensions suggests that a chimpanzee is a psychopath (or “well suited for investigations of basic biobehavioral dispositions relevant to psychopathology”).
Disinhibition refers to impulse control problems, including “lack of foresight, impaired regulation of affect and urges, insistence on immediate gratification, and deficient behavioral constraint.”
Meanness encompasses “deficient empathy, disdain for and lack of close attachments with others, rebelliousness, excitement seeking, exploitativeness, and empowerment through cruelty.”
Finally, boldness “encompasses low levels of fear/avoidance, manifest as high self-assurance and social efficacy, capacities to remain calm in situations involving threat and to recover quickly from stressful events, and a tolerance for unfamiliarity and danger.”
Latzman et al. measured the degree of expression of disinhibition, meanness, and boldness in chimpanzees by observing their behaviors and scoring the chimpanzees on different items. Disinhibition, for example, was measured by noting if chimpanzees were impulsive (“displays some spontaneous or sudden behavior that could not have been anticipated”), irritable (“easily provoked”), excitable (“easily aroused to an emotional state”) socially inept (“acts inappropriately in social settings”), attention seeking (“troubled by others who are in a desirable or advantageous situation…”), and inventive (“more likely to engage in novel behaviors”).
The researchers found that meanness and disinhibition were moderately positively correlated, as were boldness and meanness. Boldness and disinhibition, however, were insignificantly correlated.
One of the big takeaways from this research is that the triarchic model of psychopathy for chimpanzees may allow researchers to study psychopathy with non-human subjects. Chimpanzees are well suited for such investigations into psychopathy because they are so similar to humans. In addition to sharing an extremely high percentage of genes, chimpanzees also display complex socio-emotional and communicative traits. To give just a few examples, chimpanzees engage in reconciliation behavior, form coalitions with other chimpanzees, console other chimpanzees, and share food with non-kin.
Ideally, further research into psychopathic chimpanzees will give us a better understanding of psychopathy in humans and perhaps lead to a safe and effective form of treatment.