Yawns always sneak up on me at the most inopportune times: when I’m trying to look alert and professional in a business meeting, when I’m attempting to appear engrossed in conversation with a friend I haven’t seen in a long time, or when I’m on a hiking trail, at the exact moment a fly decides to dive-bomb into my mouth (true story). Occasionally, I can nip a yawn in the bud, so as not to completely aggravate my coworkers or my dinner companion. But the minute someone else in the room yawns as well, all bets are off—my mouth opens wide, like a marionette’s controlled by a puppeteer, and I suck in as much oxygen as my brain can handle. I’ve always wondered why yawning seems to be contagious, and I’m not alone. In recent years, scientists have come up with all kinds of theories in attempts to get to the bottom of the phenomenon.
Mind Games
Some people can’t stop themselves from yawning when they see someone else doing it, either in person or on video. For others, just hearing a yawn can trigger them to follow suit. And for particularly susceptible individuals, the mere thought of someone else yawning can cause them to open up. In all of these circumstances, yawn contagion appears to be largely unconscious, according to a 2005 joint study by researchers from the Helsinki University of Technology (Finland), and the Research Centre Jülich (Germany). Their investigation determined that, in contrast with other types of physical mimicry, the human brain doesn’t consciously analyze and mirror the act of yawning when it’s observed—yet it directs us to yawn anyway. So what gives?
Most likely, these researchers surmised, the sight of someone yawning deactivates an area of our brains known as the left periamygdalar region. Among the participants in this study, all of whom were asked to report the severity of their desire to yawn in response to videos of other people yawning, the researchers noted an inversely proportional relationship between their urges and this deactivation effect. In other words, the more a participant was tempted to yawn, the less active his or her left periamygdalar region appeared to be. While the researchers were not able to extrapolate any further meaning from that pattern, it did establish that humans’ proximity to yawning individuals jump-starts an identifiable cerebral reaction.
