A Yale University professor is teaching students around the world how science can help them lead a happier life. Laurie Santos started the class “Psychology and the Good Life” back in January. Nearly one quarter of Yale’s undergraduates enrolled, making it the most popular course in the school’s more than 300-year history. Now, over 138,000 people around the world have registered for the class online. Santos joined “CBS This Morning” for a crash course on happiness.