Ah, the handshake. We ditched it for the most part due to Covid-19, but we may not be able to shake this style of greeting indefinitely.

Shaking hands is deeply ingrained in human culture, perhaps more than we realize. Our close cousins, chimpanzees, use handshakes to communicate too — indicating that the behavior is part of our shared evolutionary history.

To tease out the importance of handshakes, a new study in Biology Letters takes a deep dive into hand grasping behavior among chimpanzees over the course of 12 years.

These handshake behaviors are widespread, yet separate groups of chimps have preferences dictating how they grasp hands with their neighbors.

Some prefer grasping each other’s hands, palm to palm, while others grab each other by the forearm, for example.

These differences reflect the slightly distinct kinds of handshakes we humans practice depending on where we are from in the world.

This suggests hand grasping behaviors are learned socially, as opposed to a biological trait.

It also lends weight to the idea that animals have social cultures and traditions — just like humans do.