Can physiological traits help paint a clearer picture of psychopathy?
September 5, 2012
by Robin Tricoles
Most of us can be bold, mean, or impulsive, at times. But when these three traits persist in a strong way over time, psychologists consider such behavioral tendencies psychopathic.
Traditionally a diagnosis of psychopathy is made through behavioral observations. But Christopher Patrick, a clinical neuroscientist and researcher, wants to know if these psychopathic traits have physiological signatures, hallmarks that can identify psychopathy better than observational data alone.
“When you combine meanness with disinhibition, or boldness with high disinhibition, or a combination of all three, you see someone who’s likely to be a diagnosable psychopath,” says Patrick, who has spent 25 years studying the psychopathic personality. In other words, psychopaths’ interactions with people are often competitive, abrasive, exploitive, and unfeeling.
In contrast, chronic disinhibition, or lack of behavioral control alone, would be diagnosable in some other way than psychopathy; for example, as borderline personality disorder. “Unlike the psychopath, high disinhibited individuals seem to cause distress not only for other people but also for themselves,” says Patrick. “Rather than lacking in anxiety, they show high levels of negative affect and have a lot of difficulty controlling their emotional reactions to stressors.”
Likewise, boldness itself does not make for psychopathy. Someone who is bold may appear calm in situations where others would show high distress, says Patrick. “They go into situations that are unknown and stressful and respond in a very effective way.” Take, for example, policemen working on highly stressful details, bomb disposal specialists, or even trauma surgeons. As an example of an extreme high-bold individual, Patrick cited the soldier played by actor Jeremy Renner in the Oscar-winning film, The Hurt Locker.
With these ideas in mind, Patrick is trying to figure out how to combine self-report or behavioral observations with physiological measurements to get a clearer picture of what contributes to psychopathy. These measurements include the body’s response in contexts involving fear, decision-making, and performance errors.
One such response is the startle reaction, a physiological measure useful for gauging boldness, or fearlessness. To measure the startle reaction, muscle movement corresponding to a reflex blink is recorded when a person is subjected without warning to a sudden loud noise. Research has shown that the noise-elicited startle reflex increases during viewing of unpleasant pictures or exposure to fear cues. Because of this, augmented blink-startle response during aversive cuing has been used to index fear in humans.
“The way we use the startle reflex is something like when you have a turkey in the oven and you want to check the temperature as an index of cooking status,” says Patrick. “You’ll quickly stick a probe in and check the reading.” Those with psychopathic inclinations show abnormal startle reactivity during aversive cuing. Specifically, one of Patrick’s earliest studies found that prisoners diagnosed with psychopathy do not show enhanced blink-startle reactivity to sudden noises that occurred while they viewed frightening or gruesome images.
Follow-up work by Patrick and his colleagues has shown that this reactivity deficit relates more to the boldness and meanness features of psychopathy than the disinhibitory features. This fits with the longstanding idea, dating back to the 1940s, that the core symptoms of psychopathy reflect a basic weakness in emotional response.
“This lack of emotional sensitivity is part of the psychopath’s ‘mask of sanity’, as well as contributing to his manipulative-exploitative tendencies,” says Patrick. “Someone who lacks normal anxiety and fear finds it easier to interact with new people in social situations and appear confident and credible.”
Patrick and his colleagues are currently evaluating other physiological measures, as indices of emotion in high-psychopathic or fearless individuals. Some of these other measures include brain activity at rest or in response to startling noises, and brain, facial muscle, and sweat-gland response to unpleasant visual images. Their aim is to combine these additional measures with already established ones to create a physiological index of psychopathic tendencies. What’s more, measures of this kind can be combined with self-report or behavioral observations.
“There isn’t always a perfect relationship between what people say about themselves and how they react,” says Patrick. “However, you can’t conclude that the physiology is always right and that self-report is wrong. It’s just that they’re different. So, understanding those differences along with points of overlap is important, but you can’t really get to this until you are able to measure things reliably in each domain.”
Christopher Patrick, PhD, is a professor of psychology at The Florida State University. He studies clinical neuroscience, which encompasses areas of personality, psychopathology, and human neuroscience. Patrick is current President of the Society for Psychophysiological Research and is a Past-President of the Society for Scientific Study of Psychopathy.