Believe it or not, the world is becoming a happier place, at least according to the University of Michigan Institute for Social Research's 2005 to 2007 World Values Survey. The cheeriest country?: Denmark. The gloomiest: Zimbabwe—no surprise given the political unrest there. The U.S. ranks 16th on the list, just after New Zealand. According to the research, published in the journal Perspectives on Psychological Science, people are happiest in countries with the most tolerant social norms and most democratic political systems: Iceland, Switzerland, the Netherlands and Canada all rank among the top 10 happiest countries in the world. Researchers have surveyed more than 350,000 people on how happy they have been for the past 26 years based on their responses to the same two questions: "Taking all things together, would you say you are very happy, rather happy, not very happy, not at all happy?" As well as, "All things considered, how satisfied are you with your life as a whole these days?" Democratization and rising social tolerance have even more of an impact than economic growth on happiness, although all are important contributors. The citizens of India, Ireland, Mexico, Puerto Rico and South Korea all indicate that they're becoming happier. Alas, those in Austria, Belgium, the U.K. and Germany say their joie de vivre is waning.