Are Yawns Really Contagious? What Science Says About Empathy, Temperature, and Chain Reactions
Do they really set off a chain reaction? And are you yawning right now? You might be. Find out why!
Quick Reference
- Short answer: yes. Roughly half of adults yawn back when they see someone else yawn.
- Age effect: 82 percent of people under 25 catch a yawn; 60 percent between 25 and 49.
- Temperature effect: in a 2007 study, participants holding a warm pack yawned 41 percent of the time; those with a cold pack yawned 9 percent.
- Empathy angle: children under 4, and people with autism, schizophrenia, or psychopathy, catch yawns less often.
- Cross-species: dogs catch yawns from their humans, especially familiar ones.
- Best theory today: yawning cools the brain, and contagious yawning is a bonding or empathy cue, not a tiredness signal.
Yawning is one of those mysterious reflexes that has everyone wondering, including scientists. Why do we do it, and is it really contagious? The short answer is yes on both counts, and the science behind why is more interesting than the tired-brain story you probably grew up with. Scientists still are not entirely sure why people yawn, though most agree it is a combination of things. One theory, backed by lab work and brain-imaging studies, may be the largest single contributor.
The Almanac has covered folk wisdom about tiredness, sleep, and the moon for two centuries. Modern peer-reviewed research now puts real numbers behind the old saying about catching a yawn. Below is what the current science actually shows, cross-checked against the National Institutes of Health published literature and the Psychology Today research digests on yawning behavior.
Why Do We Yawn?
Almost all vertebrates yawn: humans, apes, birds, reptiles, even fish under lab conditions. The oldest theory said yawning was a wake-up trick. Open your mouth, pull in a big lungful of oxygen-rich air, send it to the brain, feel more alert. That story does not hold up. Fetuses yawn inside the womb, where there is no fresh air to inhale, and lab experiments have shown blood oxygen levels barely move during a yawn.
The most current thinking is that yawning helps regulate brain temperature. The trigger sits in the hypothalamus, the part of the brain that runs your thirst, hunger, sleep, mood, and hormone release. Chemicals like dopamine, oxytocin, and nitric oxide flip a switch, and you yawn on instinct. If you fight the urge, you get that unsatisfied half-yawn feeling, and researchers still cannot explain exactly why.
Does Temperature Have An Effect on Yawns?
Yes, and there is a clean lab result to point at. In a 2007 study led by researcher Andrew Gallup at the University of Albany, participants held a hot or cold pack against their forehead while watching videos of people yawning. Those with a warm pack yawned back 41 percent of the time. Those with a cold pack yawned only 9 percent of the time. The Evolutionary Psychology paper is still the most-cited support for the brain-cooling theory.
Follow-up field studies in Arizona and Vienna found the same pattern outdoors: yawning peaks when ambient temperature is close to body temperature, roughly 68 to 72 degrees Fahrenheit, and drops sharply above and below that band. When it is too hot, cooling would not help; when it is too cold, cooling is already handled by breathing.
But Are Yawns Contagious?
You have heard it said and tested it yourself. You start yawning in a meeting, and everyone else starts too. Even the sound of a fake yawn sparks the chain reaction. There is a large body of evidence that yawning is, in fact, contagious. Why? Scientists are not yet ready to say for certain, but the studies point in a consistent direction.
A Social Element
Temperature is not the only factor. Yawning is also a social behavior. At least half of adults yawn when they see someone else do it, and the rate climbs with youth. Contagious yawning shows up 60 percent of the time among people aged 25 to 49, and 82 percent of the time among those under 25. The American Psychological Association summary of the research explains the age gradient by pointing to still-developing frontal-lobe empathy networks in younger people.
So yawning truly is “contagious,” although the jury is still out on why exactly. It is likely a mix of factors. One theory says yawning may be a form of communication, a bonding mechanism, or a group-wide warning about a changing situation. Wolves and chimpanzees pass yawns across the pack the same way humans do at a dinner table.
Another well-supported theory tracks contagious yawning to empathy. Multiple studies have looked at this and found that children under four years of age do not usually catch yawns yet, matching the age at which empathy circuits mature. Contagious yawning is also less common in people with autism, schizophrenia, or psychopathy, all conditions that affect empathy processing.
In one memorable study, yawns appear to be contagious between dogs and humans, and the effect is stronger when the yawner is a familiar human than a stranger.
Various studies have found that, interestingly, yawns are more likely to be catchy among friends and people who care about each other, and contagious yawning rates drop when people are among strangers. If you catch a stranger mid-yawn on the subway, odds are decent you feel nothing. Watch your best friend yawn across a coffee shop table and you will almost certainly yawn back.
Are You Yawning Right Now?
Turns out, it is not just watching. People yawn when they see photos of yawns, and even when they read about them, like right now while reading this article. Bit ironic to write, honestly.
So no need to stifle that yawn. It does not necessarily mean you are tired. It likely means you are sympathetic to the yawners around you, in person or on the page.
When You Yawn Most: Time of Day and Season
Yawn frequency follows a body-clock curve. Multiple sleep-lab studies place the two biggest yawn peaks around 30 minutes after waking and again in the last hour before bed, matching the natural body-temperature swings tracked by circadian researchers.
- Morning peak: the first 30 to 60 minutes after waking, as your core temperature rises off its overnight low.
- Afternoon dip: a smaller yawn spike between 1 and 3 p.m., aligned with the post-lunch alertness drop many desk workers know well.
- Evening peak: the hour before your usual bedtime, as body temperature starts falling to trigger sleep.
- Season note: winter yawning goes up indoors, when heated air pushes room temperature above the 72-degree Fahrenheit brain-cooling threshold. Cracking a window for 5 minutes often stops a yawn chain reaction faster than any pep talk.
Frequently Asked Questions
Are yawns actually contagious, or is that a myth?
They are actually contagious. In peer-reviewed studies, about 50 percent of adults yawn back after watching a video of someone yawning, and the rate reaches 82 percent among people under 25.
Why do we yawn in the first place?
The best-supported theory is brain cooling. When the brain warms up, chemicals in the hypothalamus trigger a deep inhalation that draws cool blood across the skull. A 2007 study showed a 41 percent yawn rate with a warm forehead pack versus 9 percent with a cold pack.
Does catching a yawn mean I am empathetic?
Probably yes. Contagious yawning correlates with empathy in multiple studies. Children under 4 rarely catch yawns, and adults with autism or psychopathy catch them less often, both groups with measurable differences in empathy processing.
Can dogs and cats catch yawns from humans?
Dogs, yes. Multiple studies have found dogs yawn contagiously when they see their owner yawn, and the effect is stronger with familiar humans than strangers. Cats appear less susceptible in the small studies to date.
Why does reading about yawning make me yawn?
The brain’s yawning circuit fires on sensory cues, including words and images that describe yawning. Just reading the word triggers the same neural pattern as watching a yawn, so the reflex often follows.
Is yawning during a conversation rude?
Not necessarily. Contagious yawning is more common between friends and people who care about each other, so a yawn can actually signal social bonding, not boredom. That said, cover your mouth.
Do animals yawn for the same reasons as humans?
Most vertebrates yawn, and the trigger appears to be similar (temperature and social cues), but only humans, chimpanzees, dogs, and a handful of other social species have been shown to catch yawns from others. Solitary species yawn alone.
Amber Kanuckel
Amber Kanuckel is a freelance writer from rural Ohio who loves all things outdoors. She specializes in home, garden, environmental, and green living topics.
- Amber Kanuckel
- Amber Kanuckel
- Amber Kanuckel
- Amber Kanuckel
I’m glad it was my bedtime when I read this article because I yawned through the whole thing..lol. It is true that young children don’t catch a yawn. I tried it many times with my son and it never worked.
It’s so interesting, isn’t it? Glad you enjoyed the article!
I yawned so hard through this article that my eyes watered. Until you mentioned our reactions to those who are unfamiliar to us. I stopped yawning at that mention and haven’t yawned since. Incredible
In 2012 I had gastric bypass surgery. Since that time I have not been able to yawn even though I feel the need to do so. I start the yawn then it just stops before I can complete the intake of breath. Have you ever heard of this before? It is really frustrating. Has anyone else experienced this following surgery?