Whether you shrug off bruises with ease or find that a stubbed toe knocks you out for a week, each of us has our own unique reaction to pain.
But scientists now say that being able to grin and bear it could be a worrying sign of a dark personality.
According to scientists from Radboud University, people who can handle greater levels of pain are more likely to be psychopaths.
The study found that people with elevated levels of psychopathy are not only more resistant to pain but less able to learn from painful experiences.
Researchers believe that this could be an important part of why people with these traits fail to learn from negative consequences.Â
During trials conducted with members of the public, those with psychopathic traits failed to change their behaviour even when faced with painful electric shocks.
This insensitivity to punishment might combine with an excessive drive towards reward to make psychopaths particularly impulsive and persistent.
Lead author Dr Dimana Atanassova says: ‘What we know from research is that people with psychopathic traits consistently fail to change their behaviour even after receiving punishment, which suggests they struggle to learn from the negative consequences of their actions.’
If you have an extremely high tolerance to pain, researchers say there is a chance you could be a psychopath like Patrick Bateman in American Psycho (pictured)Â
Psychopathy is one of the so-called ‘Dark Triad’ personality traits characterised by pathological lying, manipulativeness, lack of guilt, and tendencies towards poor behavioural control.
Not everyone with these traits is considered a psychopath and many members of the general public may have some amount of psychopathic tendencies.
Psychologists have long observed that people with these traits often fail to learn from punishment or the negative consequences of their actions.
However, researchers have been unable to explain the specific mechanism behind this deficiency.
In this paper, the researchers propose that psychopaths’ inability to learn from painful outcomes could be due to an insensitivity to physical pain.
To test this theory, 106 members of the public filled out questionnaires designed to detect levels of psychopathic tendencies such as lack of empathy or impulsivity.
After taking the test, each participant was given a series of small electric shocks via electrodes placed on their arms.
Researchers recorded the point at which the pain first became noticeable and the maximum level the participant was willing to endure.
Researchers found that people high in psychopathic traits were less sensitive to pain and were less able to learn from the painful consequences of their actions (stock image)Â
And, as the scientists had predicted, the participants who scored the highest for psychopathic tendencies were able to endure more pain than the average person.
In some cases, a few participants were even able to reach the electrode’s maximum setting of 9.99 milliamps before their pain tolerance was reached.
While it isn’t entirely clear why a psychopathic personality might be linked to pain insensitivity, the researchers did find a clear link between these traits and learning behaviour.
Dr Atanassova told PsyPost: ‘The exploitative, antisocial behavior of those with high psychopathic traits has often been looked at through the prism of callousness or lack of remorse—in a sense, that they simply don’t care about the consequences.
‘But this study’s findings suggest that the problem might be, partially, explained with a deficit in how they learn about consequences.’
In a second trial, participants were given a computer game in which they had to choose between two different coloured cards.
Every time they selected a card there was a probability of being given a reward or a negative consequence.
For the first set of 160 selections, this was either a monetary reward of €0.10 (8p) or a financial punishment of losing €0.10 (8p).
Participants were shown either a green or yellow card (pictured) and asked to choose one. Each time they chose there was a probability (shown right) to receive either a reward or a punishment of money or a small electric shock
Psychopaths, such as the Joker in The Dark Knight, failed to adapt to the punishment for making the wrong choices and tended to stick to their initial beliefs no matter the outcomeÂ
However, for the second set of choices, the participants were either given a small reward of their own choosing or an electric shock.
Since there was no way for the participants to know how the probabilities were changing, this wasn’t designed to see how well they performed.
Rather, the researchers were interested to see how the participants changed their behaviour after receiving a negative outcome.
For example, if a participant got the reward by selecting the green card three times in a row only to be shocked upon a fourth time, would they keep selecting the green card anyway?
Using a computational model called the hierarchical Gaussian filter the researchers looked at how the participants updated their beliefs throughout the test.
What they found was the people with psychopathic traits were more uncertain in their initial beliefs but soon settled on a pattern they were reluctant to budge from.
Rather than learning from a painful experience as most people do, people high in psychopathic traits showed a tendency called ‘belief resetting’.
This means that they would quickly dismiss the painful outcome and return to their original set of beliefs even when they had been proven not to work.
As these graphs show, people tended to show higher levels of uncertainty when the punishment was painful rather than financial (left). A small group of people showed a high level of ‘belief resetting’ when faced with pain (right-hand yellow graph) meaning they quickly reverted back to their original ideas after being electrocuted. This group tended to test much higher for psychopathic traits
The researchers suggest that this could explain why psychopaths continue to make destructive life choices even when the outcomes negatively affect them (stock image)
Interestingly, this pattern only emerged in the set of choices where pain was given as a consequence of wrong choices.
The researchers say this could point to pain insensitivity as the root cause of the psychopathic inability to learn from experience.
Dr Atanassova says this could also help explain why psychopaths continue with their antisocial behaviour even when it causes them problems.
‘One of the hallmarks of psychopathy is aggressive, exploitative behavior with little regard for the wellbeing of others,’ Dr Atanassova explains.
‘They persist with a given course of action even when they suffer painful consequences due to a combination of insensitivity to pain and an impairment in an underlying cognitive learning mechanism.
‘Given the propensity of those with psychopathic traits to engage in violence and aggression, understanding why they don’t learn from negative consequences and how they process pain is essential’
