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- Psychopaths can be hard to spot.
- This is because they’re not all murderers or criminals.
- Many are successful business people, surgeons, and even journalists.
- Researchers have come up with a new test for psychopathy.
- According to a new study, psychopaths’ pupils do not dilate when they see something troubling or scary.
- This is probably because they do not tend to feel threatened.
Think you could spot a psychopath? They often blend into the background, so chances are you probably can’t.
The study, published in the journal Personality Disorders: Theory, Research, and Treatment, involved 82 male mentally disordered offenders. The researchers examined how their pupils reacted to visual images of real-world scenes, auditory sound clips, and videos of dynamic facial expressions. Some of the pictures were nice, like puppies, and some were negative, such as bloody injuries.
Psychopaths and non-psychopaths were watched closely, and the results showed that while the pupils of non-psychopaths’ eyes dilated when viewing something scary, the psychopaths’ pupils did not.
Pupils can show what we’re thinking
Usually, our pupils dilate when we see something that upsets or offends us, due to an adrenaline rush caused by the “fight, flight, or freeze” response. They also get bigger if we see something that excites us, which is why sophisticated card players often look at their opponents’ eyes to see if they have a good hand.
As psychopaths didn’t seem to have such a strong reaction to horrible imagery, it suggests they aren’t so susceptible to feeling threatened or scared.
“The pupil has long been known to be an indicator of a person’s arousal,” said Dan Burley from Cardiff University’s School of Psychology. “The pupil usually dilates when an image shocks or scares us. The fact that this normal physiological response to threat is reduced in psychopathic offenders provides us with an obvious physical marker for this condition.”
Experts have sometimes suggested that psychopaths don’t experience emotions like the rest of us do. For example, Adrian Raine, a professor of criminology at the University of Pennsylvania and expert on psychopathy, told INSIDER that psychopaths tend to have a “blunting of emotions.”
“Psychopaths are more likely to be thrill seekers, and more likely to push the envelope on life,” he said. “You know, do daring things. It’s because they lack fear and they lack conscience. If we thought about doing something a little bit scary, we’d get scared.” Psychopaths, on the other hand, don’t.
The biology of a psychopath
The amygdala is the area of the brain where people process emotions. In psychopaths, this area is up to 18% smaller. When most people are given a moral dilemma to consider, such as the trolley problem, the amygdala fires up and lights up on brain scans. In psychopaths, this doesn’t happen to the same degree.
“We know that there are strong genetic contributions to the brain areas, but we also know that the social environment can impact the brain,” Raine said. “People who are abused early in life or who are neglected, for example, they have a reduction in the volume of the amygdala. That’s at least true in children. So it can be genes and it can be the environment. Most likely, it’s a combination of both.”
Surprisingly, in the new study, the psychopathic offenders’ pupils responded normally to positive images like happy couples and animals, which suggests psychopathy may not be associated with a complete lack of emotions, but a reduced sensitivity to threatening information.
Their pupils also dilated when seeing smiling faces, which the authors suggest could be because psychopaths are sometimes suspicious of people who appear happy.
“Many psychopathic offenders appear to be bold, confident, and can act in cold-blooded manner,” said Robert Snowden from Cardiff University. “It’s much easier to act bold if you have no feelings of fear, and to be cold-blooded if there is no emotion to get in the way of the act.”