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Watch: This extremely human behavior was just observed in animals

Raphaela Heesen and Emilie Genty

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How do you start and end a conversation?

With a greeting, of course — be it a handshake, saying hello or goodbye, a hug, nodding, bowing, or waving.

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Greetings are intrinsically human, no matter where you’re from. Scientists previously thought this collective social behavior was also unique to humans.

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But a new study shows that chimps and bonobos also greet each other at the beginning and end of their social interactions.

This behavior is described in a report published this week in the journal iScience.

Researchers documented how different primates initiate and end social activities with eye contact and gestures.

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Here’s what that behavior looks like in chimps:

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Two chimps greet each other with mutual eye contact and close gestures before a grooming ritual.Raphaela Heesen and Emilie Genty
When they were done playing, these two chimps said goodbye by gesturing and gazing at each other.Raphaela Heesen and Emilie Genty

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In bonobos, the length of each greeting varied based on the closeness of each pair’s relationship.

If the two apes knew each other well, they would spend less time greeting each other.

Sounds a lot like humans, no?

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“When you’re interacting with a good friend, you’re less likely to put in a lot of effort in communicating politely.”

Raphaela Heesen, lead study author

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Raphaela Heesen and Emilie Genty

The findings show that this type of collective, society-wide behavior, which researchers dub joint commitment, isn’t just found in humans.

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It also sheds light on how our social systems evolved similarly to those of apes.

If we both do something, our shared ancestors probably did, too.

Read more stories about animals here.

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