medicalexpress | People with psychopathic characteristics are
less likely to be affected by "contagious yawning" than those who are
empathetic, according to a Baylor University psychology study.
Yawning
after spotting someone else yawn is associated with empathy and
bonding, and "catching" yawns happens with many social mammals, among
them humans, chimpanzees and dogs, researchers say.
The study—"Contagious yawning and psychopathy"—involved 135 college student respondents and was published online in the journal Personality and Individual Differences.
"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 an antisocial lifestyle, including
being selfish, manipulative, impulsive, fearless, domineering and, in
particular, lacking in empathy, previous research has shown.
Students in the Baylor study 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, students were seated in a dim room in front of computers. 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.
They were shown 10-second video clips of different facial movements—a
yawn, a laugh or a neutral face—with 10 seconds of blank screen
separating 20 video snippets of those expressions.
Based on the psychological test results, the frequency of yawns and
the amount of physiological response of muscle, nerve and skin, the
study showed that the less empathy a person had, the less likely he or she was to "catch" a yawn.
