Baby Monkeys Smile Similarly To Human Babies

Researchers at Kyoto University have found that baby Japanese Macaque Monkeys smile spontaneously during sleep. The University’s Primate Research Institute said that such smile had earlier been confirmed among only human infants and baby chimpanzees. For humans, the smile is believed to mean a cheerful attitude, but for Japanese Macaque monkeys, scientists think it may be a way to develop cheek muscles.