Chimpanzees Can Vary Smiles like Humans, Says New Study

Chimpanzees have the same types of smiles as humans when laughing, says a new study published in the journal PLoS ONE. The study also found that chimpanzees are able to produce these smile types silently, without being constrained by the accompanying laughing sound. The ability to flexibly produce facial expressions and vocalizations has a strong [...] —> Read More