The perception is something that most probably does every day, but it's strange that scientists are still not sure why.
Recently, the scientific community has moved to the idea that yawning is a thermoregulatory behavior that cools the brain, but its true biological function is still unclear.
Moreover, scientists are not quite sure why it is contagious among social animals like humans. In a 2005 study published in Cognitive Cancer Research, we found that networks in the brain responsible for empathy and social skills are activated when they see someone yelling. The researchers also noted that chimpanzees can "catch" people's nostrils.
"Copying facial expressions to others helps us to accept and understand their current situation," said Dr Matthew Campbell of the Emory University Research Center for Primary Research.
Therefore, according to a study, psychopaths are not so sensitive to contagious yawning.
Read more: Catching someone's eye is associated with empathy, and psychopaths are often immune