It's Okay to Be Smart

The Only Animal That Weeps

Season 5 Episode 30 | 4m 24s Video has closed captioning.

Why do we cry? It’s weird. Humans leak water out of their faces when they get sad. Are we the only animals that do this? What does it mean? What is it for? Here’s the science of human tears!

Aired: 07/24/18

Rating: NR

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Problems Playing Video? | Closed Captioning