A study involving giggling babies proves a closer connection between the primates. The study published in the journal, Current Biology, measured the giggling sounds of human infants and chimpanzees, concluding that we share the "human" emotional response of laughter with the great apes.

The results do not come as a huge surprise to the scientific community as chimpanzees, gorillas, humans and orangutans are all more closely related to each another than they are to the gibbons, or lesser apes. Baby chimpanzees and human infants emit the same giggling sounds when tickled as laughter evolved millions of years ago in one of our common ancestors.