Why We Yawn and Why It’s Contagious

Why Do We Yawn, and Why Is Yawning Contagious?

Yawning is one of those seemingly simple actions that carries a surprising amount of complexity. At its core, yawning is the act of inhaling air deeply, stretching your eardrums, and often popping your ears in the process. When this is paired with a full-body stretch, it’s known as pandiculation. But why do we yawn? And why does seeing someone else yawn—or even just thinking about it—make us want to yawn too?

The Oxygen Myth and the Real Reason Behind Yawning

A common belief is that yawning happens when we need more oxygen. However, studies have debunked this idea, showing that yawning frequency isn’t tied to oxygen levels. For example, during exercise, when our bodies demand more oxygen, we don’t necessarily yawn more. So, if yawning isn’t about increasing oxygen intake, what is it about?

Recent research points to brain temperature as a key factor. When we’re tired or exhausted, the temperature of our brain tends to rise. Just like a computer, our brain functions best within a specific temperature range. Yawning, it turns out, helps cool down the brain. By drawing in outside air, yawning cools the blood flowing to the brain, bringing it back to its optimal temperature.

This cooling effect can be particularly observed in animals like parakeets. Researchers have found that parakeets yawn within a narrow temperature range—when it’s too cold, they don’t yawn because it would cool their brains too much, and when it’s too hot, they don’t yawn because it would have the opposite effect. Interestingly, unlike humans, parakeets don’t exhibit contagious yawning, which brings us to the next intriguing question: Why do humans yawn when others do?

The Contagious Nature of Yawning

If you’ve ever watched someone yawn and found yourself immediately doing the same, you’ve experienced the contagious nature of yawning. But what causes this? Research suggests that contagious yawning is closely tied to brain temperature regulation and social bonding.

In one study at the University of Albany, researchers found that people were less likely to yawn contagiously if they had an ice pack on their forehead. The cooling effect seemed to reduce the need to yawn, supporting the theory that yawning helps regulate brain temperature.

However, contagious yawning isn’t just about cooling the brain—it’s also linked to empathy. Yawning increases blood pressure, stretches facial muscles, and boosts focus, which might explain why it can be contagious among social animals, including humans. In a herd of prey animals, for instance, one animal yawning could serve as a signal to the others to stay alert, a behavior that would have evolutionary advantages.

Yawning and Empathy: A Deeper Connection

The connection between yawning and empathy is fascinating. Empathy is the ability to understand and share the feelings of others, and contagious yawning seems to be a manifestation of this. Studies have shown that children with autism, who often struggle with social interaction, are less likely to yawn contagiously when watching others yawn. This suggests that contagious yawning might be an expression of emotional contagion, where the emotions of those around us influence our own feelings.

Further research from the University of Pisa found that contagious yawning is most common among close family members, followed by friends, acquaintances, and lastly, strangers. This pattern aligns with the idea that yawning is linked to empathy—people are more likely to yawn contagiously around those they care about.

Supporting this, a study from Leeds University showed that participants who scored higher on empathy tests were also more likely to yawn when someone else did. This suggests that contagious yawning isn’t just a random occurrence; it’s a reflection of our ability to connect with and understand others.

Yawning in the Animal Kingdom

Yawning isn’t unique to humans—many animals yawn, but they do so for different reasons. For example, guinea pigs and some monkeys yawn to show off their teeth and intimidate rivals. Penguins use yawning as part of their courtship rituals, while snakes yawn to realign their jaws and open their airways after a large meal.

Fish, on the other hand, yawn more frequently when oxygen levels in the water are low or when the water temperature is high. These examples show that while yawning is a common behavior across species, the reasons behind it can vary widely.

The Ancient Signal of Survival

In humans, yawning likely served an ancient purpose—an evolutionary signal to stay alert and ready for action. When you yawn, you’re participating in a behavior that connects us with many other animals, but in a way that’s uniquely human. It’s a reminder that, at its core, yawning is about survival, empathy, and connection.

So, the next time you find yourself yawning, whether spontaneously or contagiously, remember that this simple act is part of a complex and ancient mechanism that helps keep us connected and ready for whatever comes next.