Researchers Develop Model to Assess Psychopathic Personality Tendencies in Chimps

According to Hervey Cleckley’s The Mask of Sanity, psychopathic personality entails a severe disturbance in behavioral control, social relations and emotional experience concealed by an outward appearance of normality. Although psychopathy has traditionally been studied in forensic samples, and sometimes, the general population, a team led by Georgia State University researchers is now studying these tendencies in chimpanzees.

These tendencies, or biobehavioral dispositions—disinhibition, boldness and meanness—are described in the Triarchic Model of Psychopathy for humans.

The research provides a foundation for better understanding not only the nature and origin of psychopathic tendencies in humans but also, consistent with recent National Institutes of Health priorities, lays the groundwork for understanding the underlying biological basis of other clinical conditions.

“It’s important to note that we are not diagnosing nor are we interested in diagnosing psychopathy here,” said lead researcher psychology Professor Robert Latzman. “The work we’re doing focuses on leveraging data collected from chimpanzees to understand basic dispositional processes associated with mental illness.”

Latzman, Professor William Hopkins of the Neuroscience Institute and Florida State University psychology Professor Christopher Patrick led the research, which included 238 captive chimpanzees.

The three-part study was conducted as follows:

  • The researchers began their work by creating scales, the CHMP-Tri Scales, to assess the three traits. Using an existing chimpanzee personality measure, the team identified items to assess each of the three dispositional tendencies included in the Triarchic Model.
  • Next, the team established the translational value of their work. To achieve this, humans were administered both the chimpanzee-developed CHMP-Tri scales (from study one) and a traditional human-developed measure of the same construct. The researchers found that the CHMP-Tri scales, although developed in chimpanzees, were able to effectively index triarchic dimensions in humans, underscoring the translational value of their work with chimpanzees.
  • For the third study, Latzman and the team returned their focus to the chimpanzees to determine if the scales were able to actually predict previously collected task-based behavioral data. Specifically, the researchers used behavioral tasks indexing approach-avoidance behavior, expected to correlate with boldness, and the ability to delay gratification, expected to correlate with disinhibition. For example, to test the ability of the boldness dimension to predict approach-avoidance behavior, chimpanzees were presented with a novel stimulus, a human mannequin, while researchers tracked their behaviors. If the model scales were accurate, chimpanzees rated higher on boldness tendencies would more regularly approach the human mannequin.

The CHMP-Tri scales accurately predicted the task-based behaviors as expected. The chimpanzees with higher boldness tendencies approached the mannequin more often, further validating the model in chimpanzees.

Patrick, who developed the original Triarchic Model of Psychopathy in humans, pointed out the research’s significance to clinical conditions beyond psychopathy.

“This work will contribute in a transdiagnostic manner to an understanding of other clinical conditions,” he said.

Latzman said that the work is a nice demonstration of the type of innovative, noninvasive research that can be conducted with chimpanzees.

“The translational value of chimpanzee research to understand key neurobehavioral constructs important to understanding mental illness is clear,” he said.

“The Chimpanzee (Pan troglodytes) Model of Triarchic Psychopathy Constructs” paper is now available online on the Clinical Psychological Science website.