Tibetan Buddhist monk Matthieu Ricard, who is originally from France, earned the moniker "world's happiest man" after brain scans taken during a neurological study on meditation (led by Dr. Richie Davidson) showed excessive activity in his brain as he meditated on compassion. A staunch vegetarian, Ricard talks about the importance of extending compassion to all beings, including animals, which he lays out in his new book, "A Plea for the Animals: The Moral, Philosophical, and Evolutionary Imperative to Treat All Beings with Compassion."