Why Do We Yawn? A Deep Dive Into the Science Behind It

Yawning: it’s one of the most contagious and mysterious human behaviors. Whether you’re tired, bored, or simply see someone else do it, the urge to yawn can strike at any time. But what’s really happening in the body when you yawn—and is it a bad thing?

Let’s unpack what science has to say about this oddly powerful act.

What Is Yawning, Biologically Speaking?

A yawn is an involuntary reflex where you open your mouth wide, inhale deeply, and then exhale. This action stretches the eardrums, increases your heart rate slightly, and sometimes even causes your eyes to water.

For decades, the most common explanation was that yawning helps bring more oxygen into the body and remove a buildup of carbon dioxide. This “oxygen theory” made intuitive sense—especially since we tend to yawn in stuffy rooms or when we’re inactive. But as more studies emerged, this idea started to lose its grip.

The Oxygen Theory: Outdated But Not Fully Disproven

Initial research from the 1980s proposed that yawning served a respiratory purpose: to increase oxygen levels and rid the body of carbon dioxide. However, in a landmark study by Provine et al. (1987), participants were exposed to air with high levels of oxygen and carbon dioxide. Surprisingly, their yawning frequency didn’t change significantly.

Conclusion: While breathing changes do accompany yawning, it likely isn’t just about oxygen or carbon dioxide. The mechanism is more nuanced.

The Brain-Cooling Theory: A New Front-Runner

A more recent and compelling explanation? Yawning helps regulate brain temperature.

According to studies led by Andrew Gallup and others, yawning increases blood flow and cools the brain, especially in warm environments or during mental fatigue. Think of it like your brain hitting a reset button to perform better under strain.

Study Spotlight: In a 2007 study published in Evolutionary Psychology, participants were less likely to yawn when cold packs were applied to their heads, supporting the idea that cooling the brain suppresses yawning.

So, when you’re tired or overworked, your brain may be overheating—and yawning kicks in to help recalibrate.

Yawning and Fatigue: More Than Just Sleepiness

Yawning often happens when we’re tired or drowsy. But it’s more accurate to say that yawning is associated with transitions between states of alertness and rest. It often occurs before sleeping, upon waking, or during long periods of inactivity.

Yawning may act as a “bridge” behavior—nudging your nervous system to shift between alertness and relaxation. It’s not necessarily a red flag, but a signpost of your body moving through different modes.

Social and Psychological Yawning: Contagion Is Real

Have you ever yawned just because someone else did? That’s not your imagination. Contagious yawning is well-documented, and it appears to be linked to empathy and social bonding. Humans, chimpanzees, and even dogs exhibit this behavior.

Fun fact: People with higher empathy scores are more likely to catch yawns from others. Neuroimaging studies show that areas of the brain responsible for social awareness and mirroring behavior light up during this phenomenon.

Is Yawning Bad for You?

No. Yawning is a normal and healthy behavior. It’s not a problem unless it becomes excessive and persistent.

Frequent yawning—especially if it’s not tied to sleepiness or boredom—might point to:

• Sleep disorders (e.g., sleep apnea)

• Medication side effects (especially SSRIs or opioids)

• Neurological issues (very rarely, excessive yawning may be associated with brainstem issues or MS)

If yawning is happening constantly and disrupting daily life, it’s worth checking with a healthcare provider. But for most people, it’s simply a natural response to internal or external changes.

Natural Ways to Support Alertness: Essential Oils That Help

If you’re yawning through the mid-afternoon slump or finding it hard to stay mentally sharp, aromatic support from essential oils can be a powerful tool. doTERRA’s essential oil blends are known for their ability to stimulate the senses and shift mental states quickly and naturally.

Here are a few standouts:

Peppermint Oil

A classic for a reason. Peppermint oil has been shown to increase alertness, improve cognitive performance, and even reduce fatigue. Try a drop in the palms, rub together, and inhale deeply—or diffuse during work sessions.

doTERRA Motivate® Encouraging Blend

A blend of peppermint, clementine, coriander, basil, yuzu, melissa, rosemary, and vanilla. This blend is designed to kickstart confidence and drive—perfect for breaking out of a sluggish, yawning mindset.

doTERRA InTune® Focus Blend

Especially helpful for prolonged mental work or long meetings. InTune includes sandalwood, frankincense, lime, patchouli, ylang ylang, and Roman chamomile. Apply to temples or the back of the neck for focus and clarity.

doTERRA Adaptiv® Calming Blend

While not directly stimulating, Adaptiv helps regulate stress responses—helpful when yawning is tied more to nervous tension or burnout. It contains wild orange, lavender, copaiba, spearmint, and magnolia, supporting a calm but alert state.

Yawning Isn’t Lazy—It’s Smart

Your body is wise. Yawning is not a weakness or a failure to stay engaged. Instead, it’s a subtle signal that your brain needs a recalibration—whether to cool down, re-engage, or switch modes. With simple tools like movement, breathing, hydration, or aromatherapy, you can meet your body’s cues with awareness instead of resistance.

So next time you yawn—don’t fight it. Breathe into it, stretch, and maybe even reach for a little peppermint oil. Your body is trying to help you stay sharp.