Yawning functions to cool the brain and increase alertness

the verdict

SUPPORTED

the evidence backs this

Recorded sources

4 sources for · 0 against

Counts group repeated records of the same source within each side. They do not measure evidence strength or source independence.

Is it true that yawning functions to cool the brain and increase alertness?

Yes. Multiple studies support the hypothesis that yawning functions as a thermoregulatory mechanism to cool the brain and modulate alertness or arousal.

Verdict: SUPPORTED · 4 sources for, 0 against · Last checked 4 Aug 2026

The analysis

The retrieved papers provide consistent empirical support for the thermoregulatory and arousal functions of yawning across multiple vertebrate species. Studies directly link temperature manipulations, brain size, and thermal changes to yawning frequency and duration, without any papers refuting the core physiological hypothesis.

Evidence for · 4

Yawning as a Brain Cooling Mechanism: Nasal Breathing and Forehead Cooling Diminish the Incidence of Contagious Yawning

2007

Gallup et al. (2007) demonstrated that nasal breathing and forehead cooling reduce contagious yawning, supporting yawning as a thermoregulatory mechanism.

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Gallup, A. C. & Gallup, G. G. (2007). Yawning as a Brain Cooling Mechanism: Nasal Breathing and Forehead Cooling Diminish the Incidence of Contagious Yawning. doi.org. https://doi.org/10.1177/147470490700500109

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More for · 3

CHANGES IN AMBIENT TEMPERATURE TRIGGER YAWNING BUT NOT STRETCHING IN RATS

2010

Shoup-Knox et al. (2010) found that ambient temperature changes trigger yawning in rats, supporting its link to cerebral cooling and arousal.

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Gallup, A., Miller, R. R., & Clark, A. (2010). CHANGES IN AMBIENT TEMPERATURE TRIGGER YAWNING BUT NOT STRETCHING IN RATS. doi.org. https://doi.org/10.1111/J.1439-0310.2010.01854.X

Brain size and neuron numbers drive differences in yawn duration across mammals and birds.

2021

Massen et al. (2021) showed robust positive correlations between brain size, neuron number, and yawn duration across species, reinforcing the brain cooling hypothesis.

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JJM, M., M, H., JS, M., EB, L., J, H., M, K., S, O., Y, Z., C, O., JW, V., T, B., P, N., & AC, G. (2021). Brain size and neuron numbers drive differences in yawn duration across mammals and birds.. doi.org. https://doi.org/10.1038/s42003-021-02019-y

Differential potentiation of odor aversion and yawning by melanocortin 4 receptor signaling in distinct regions of the ventral striatum.

2025

Hsu et al. (2025) observed that melanocortin-induced brain temperature elevations were followed by yawning, supporting its thermoregulatory function.

Get citation

MT, A., MM, A., S, S., Y, M., M, T., & M, Y. (2025). Differential potentiation of odor aversion and yawning by melanocortin 4 receptor signaling in distinct regions of the ventral striatum.. doi.org. https://doi.org/10.3389/fnins.2025.1668410

Related receipts

Is it true that Yawning is caused by a lack of oxygen in the brain? REFUTED related question, same topic
Is it true that Yawning helps regulate brain temperature by cooling the brain? PARTIAL LEAN related question, same topic

What does the evidence say?

Receipt History

first checked04 Aug 2026

judged → SUPPORTED · 8704 Aug 2026

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