The most important aspect to health and happiness is the quality of our relationships. The longest study ever conducted on happiness has demonstrated this. Robert Waldinger, MD, and Marc Schulz, PhD are the current director and associate director of the 85-year-old Harvard Study of Adult Development. This study, as well as a plethora of additional research, is discussed in the book they co-authored called The Good Life: Lessons From The World's Longest Scientific Study of Happiness: that describes how we can live a happier, healthier, and more meaningful life.