Long before humans were able to talk, we did a lot of laughing and crying. Over the millenia, both those noises have been the soundtrack to our lives' most memorable moments - births, first words, first loves and final losses. Researchers will tell you these vocal human emotions are still poorly understood, however, science is beginning to show that these two seemingly unrelated behaviours have a lot in common. A new documentary for The Nature Of Things is all about that and Mike Downie is the director and one of the writers of Laughing And Crying. (He also happens to be the brother of the late and beloved Gord Downie of the Tragically Hip.) He spoke with Russell Bowers.