I like that we’re always learning ways in which animals exhibit behavior that was once considered to be exclusively human. It reminds me that we are part of nature; closely related to and intricately linked to our fellow creatures.

From the BBC Nature:

Gorillas bare their teeth in a playful “grin” to reassure one another during play, scientists have discovered.

This “flash of teeth” seems to let their playmate know that they do not intend to harm them.

The researchers, from the University of Portsmouth, study the facial expressions of primates to uncover the evolutionary origins of human smiling and laughter.

They published their findings in the American Journal of Primatology.

Lead researcher Dr Bridget Waller explained that non-human primates have two expressions “that shed light on our smiling”.

Their “playface”, she explained, appears to be a foundation of human laughter.

Read more here.