Yawns are weird. You’re tired? Why don’t you open your mouth really big about it? What’s that? You’re not tired, but you saw someone else open their mouth big? Well, guess what.
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[–] 9 points 11 months ago (1 child)

My idea is that yawing helps sync our internal clocks. So, we sleep at the same time, and wake up at the same time. That way, no one is left behind when the group starts moving to the next waterhole, or feeding ground.

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