Researchers have tickled gorillas, bonobos, chimps and humans in an effort to understand the evolution of laughter in the primate world.

Can hearty laughter have some of the same physiological effects as exercise?

A comedian and a neuroscientist walk into a bar.. er, nevermind. Tig Notaro and Robert Provine talk about why we laugh at even the grimmest of subjects, like cancer and death.

Author Scott Weems lets us in on the jokes and uncovers the science of humor.