Here's The Reason Why Yawns Are So Contagious

It happens before sleeping. It happens when you wake. It happens if you're bad or good. No, not Santa Claus creepily spying on you — yawning. But if dirty old Saint Nick does watch you prepare for bed and wake up in the morning, he probably sees you yawn, causing him to yawn, too. Even if you don't hear Santa yawning, "Ho-ho-ho" into your ear at night, you probably know from firsthand experience that yawning is incredibly contagious. In fact, you might be yawning now because, according to Psychology Today, simply "reading the word 'yawn' can make people yawn." What makes human bodies behave this way? Here's what science says.

Per Live Science, contagious yawning belongs to a class of behaviors called "echophenomena," whereby people reflexively imitate another person. People also imitate others' words (known as "echolalia") and actions (known as "echopraxia"). With respect to yawning, the imitation is connected to heightened activity in the motor cortex, the part of the brain that also controls "goal-directed movements." A study published in 2017 found that using electrical currents to stimulate the motor cortex actually strengthens the impulse to imitate others' yawns. Weirdly, trying to stop yourself from yawning also increases the urge to yawn.

So is contagious yawning just a neurological oddity? We don't know, but the phenomenon may be closely tied to your capacity for empathy. A 2013 paper in the International Journal of Applied Basic Medical Research noted that children with a form of autism, which impairs social skills, exhibit less contagious yawning than non-autistic children. Similarly, people with schizophrenia are less affected by contagious yawning.

In line with those findings, neuroimaging studies indicate that the parts of the brain related to empathy  are also activated during contagious yawning. This has also been shown to happen in chimpanzees, proving the age-old adage, "monkey see, monkey do." Contagious yawning might also serve as an indicator of a dogs' emotional bond to their owner. Though dogs also yawn when stressed, Live Science reported that researchers at the University of Tokyo found that even when dogs aren't stressed, they yawn more frequently when their owners yawn, ironically making your dog a total copycat. 

But while empathy is definitely a plausible explanation, the matter isn't settled. Researchers at Duke University conducted a comprehensive study of contagious yawning and didn't find a connection to empathy.  Rather, they determined that "age was the most important predictor of contagious yawning, and even age was not that important." Moreover, "the vast majority of variation in the contagious yawning response was just not explained." If that lack of clarity frustrates you, we totally empathize.