So you’re out with friends, or worse, at a business meeting, when you see someone yawn. Soon, you’re yawning too.
Why does this happen? Researchers believe that yawning is contagious because it is linked to empathy, and most humans have lots of empathy.
This behavior is deeply rooted in our evolutionary history. Many mammals yawn. And yawning by one member of a group often begets yawning by another member of the group. This happens among people — and also among dogs and chimpanzees.
But it doesn’t happen among psychopaths.
Research on yawning
Brian K. Rundle and colleagues at Baylor University in Texas recently published a paper entitled, Contagious yawning and psychopathy. The bottom line: People who were high in psychopathic traits were less likely to yawn in response to yawns by others.
A total of 135 students participated in the research. They completed the Psychopathic Personality Inventory (PPI), which produces scores for fearless dominance, self-centered impulsivity, and coldheartedness.
The students were asked to sit in a comfortable chair in front of a computer. Researchers attached electrodes to their faces to measure physiological responses, and the students wore noise-cancelling headphones.
Then they watched a video that included people yawning. The researchers observed who yawned in response, and how often.
The researchers expected to find a connection between psychopathic traits and a decreased susceptibility to contagiously yawn. They did.
According to the study results, students who scored high on the coldheartedness factor of the PPI yawned less frequently than the other students.
“Our results, then, fit well into the evolutionary model that contagious yawning in our species is a function of empathy, as we have shown that those who are characteristically lacking in empathy are less susceptible to a contagious yawn when prompted in a paradigm known to induced contagious yawning in normal individuals,” Rundle and colleagues wrote.
What do you think? Did you ever notice that the sociopath you know didn’t yawn when others did?