Elena Scotti/FUSION

Well? Did you yawn?

If you did, you may be an especially empathetic person. And if you didn’t? You are a psychopath. Just kidding! But according to a small new study published in the journal Personality and Individual Differences, people with psychopathic qualities may be less likely to yawn when they see someone else do so.

In the study, 135 college students completed a Psychopathic Personality Inventory, or PPI-Revised, which tests for certain psychopathic traits. But while the two behavioral aspects of psychopathy ("fearless dominance" and "impulsive antisociality") were not associated with yawning, the researchers did see a link between the emotional aspect ("coldheartedness") and yawners. Allow me to explain.

After the students completed the inventory, the researchers noted which participants scored in the top 35% of the group for "coldheartedness"—which is defined by "a lack of social emotion." While this didn't qualify them as psychopaths, it did provide information about their level of empathy, which proved useful later on.

The researchers then subjected the participants to two separate experiments. In the first, the participants sat in a dimly lit room, put on noise-canceling headphones, and watched 20 sets (or blocks) of three randomly arranged videos: one of someone with a neutral face, one of someone laughing—these two were controls—and one of someone yawning. During the viewing, the researchers recorded how many times the participants yawned.

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The researchers recorded 133 yawns total among the 135 participants—participants who were not particularly coldhearted averaged about 3.36 yawns per 20 sets. Those who were more coldhearted averaged 1.96 yawns per 20 sets.

In the second experiment, only the male participants took part in an emotion-related startle paradigm—a well-known measure of psychophysiological activity. (The physiology of being "startled" is a bit more complex in women, so for clarity's sake, they were omitted.)

The participants again sat in a dimly lit room and put on noise canceling headphones, but this time they looked at a series of pictures meant to evoke emotional responses—from puppies to to robberies to two people simply having a conversation. Throughout the slideshow, the researchers randomly played bursts of white noise, recording the participants' facial electrical activity (how often and hard they blinked), as well as their skin response.

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Normally, people's startle response will vary depending on the visual stimulus—if they're looking at a picture of a basket of kitties, for example, the burst of noise will startle them, but it will startle them more if they're looking at a disturbing photo of a crime scene. Psychopathic people, meanwhile, have the exact same startle response to the burst of white noise, whether they're looking at kitties, a crime scene, or anything else. A lower startle response is associated with psychopathic tendencies.

The researchers found that those with a lower startle response were strongly linked to those with a lower susceptibility to contagious yawning. Conversely, those who were more affected by the startle paradigm were more likely to catch yawns.

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"The take-home lesson is not that if you yawn and someone else doesn't, the other person is a psychopath," Brian Rundle, study author and doctoral student at Baylor University, said in a press release. Many people didn't yawn, he continued, which wasn't all that surprising, since people do not yawn in response to "a stranger we don't have empathetic connections with.”

For Rundle, the most important finding was that there may be a neurological link between psychopathy and yawning, and that contagious yawning is a function of empathy—a potential jumping off point for future research. "We’re always looking at the brain in the context of really complex behaviors," Rundle told me.

The study does, however, appear to show a :relationship between two complex behaviors," he said. "It allows us to neurologically understand both yawning and psychopathy independently but also in relationship to each other."

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So great! You’re most likely not a psycho killer. But if you look at this yawning GIF and feel nothing inside, then you might actually be at least a little psycho.