People with psychopathic traits are less likely to “catch” a yawn compared to those who are empathetic, according to a new study at Baylor University.
Yawning after seeing another person yawn is associated with empathy and bonding, and “catching” a yawn happens often among mammals who are social, including humans, chimpanzees, and dogs, say researchers.
“You may yawn, even if you don’t have to,” said lead researcher Brian Rundle, a doctoral student in psychology and neuroscience in Baylor’s College of Arts and Sciences. “We all know it and always wonder why. I thought, ‘If it’s true that yawning is related to empathy, I’ll bet that psychopaths yawn a lot less.’ So I put it to the test.”
Psychopathy is characterized by a lack of empathy, being selfish, manipulative, impulsive, fearless, and domineering, according to previous research.
For the study, 135 students at Baylor first took a standard psychological test — the 156-question Psychopathic Personality Inventory, with questions aimed at determining their degree of cold-heartedness, fearless dominance, and self-centered impulsivity.
“It’s not an ‘on/off’ of whether you’re a psychopath,” Rundle said. “It’s a spectrum.”
Next, the participants were seated in front of computers in a dimly lit room. They wore noise-canceling headphones, with electrodes placed below their eyelids, next to the outer corners of their eyes, on their foreheads and to index and middle fingers.
The students proceeded to watch 10-second video clips of different facial movements, such as a yawn, a laugh, or a neutral face. Separating these 20 video snippets of facial expressions were 10 seconds of blank screen.
Based on the psychological test results, the frequency of yawns and the amount of physiological response of muscle, nerve, and skin, the findings revealed that the less empathy a person had, the less likely he or she was to “catch” a yawn.
“The take-home lesson is not that if you yawn and someone else doesn’t, the other person is a psychopath,” Rundle cautions. “A lot of people didn’t yawn, and we know that we’re not very likely to yawn in response to a stranger we don’t have empathetic connections with.
“But what we found tells us there is a neurological connection — some overlap — between psychopathy and contagious yawning. This is a good starting point to ask more questions.”
The study, entitled “Contagious yawning and psychopathy”is published online in the journal Personality and Individual Differences.
Source: Baylor University