By Christine Hsu | Nov 19, 2012 04:05 PM EST
Study revealed that like humans, the wellbeing or happiness of chimpanzees and orangutans also follows a U shape and is high in youth, falls in middle age and rises again into old age.
By Nikki Tucker | Aug 23, 2012 03:58 PM EDT
According to a Japanese study, scientists found evidence demonstrating a rare physiological similarity between gibbons and humans.
