After 88 years of research by scientists at Harvard University, the world's longest study on happiness is still ongoing. The study, which compared the lives of two groups of young White men, began in 1938 and has since added hundreds more participants, including women and children. The research has found that the best predictors of a happy and meaningful life were not wealth, fame, hard work, intelligence, or even 'good' genes. Instead, the researchers found a surprising connection between close relationships and how good our lives feel to us. Those most satisfied with their community of friends and family in middle age were found to be the healthiest at age 80, less likely to have diseases, and more likely to recover from illnesses. Critics argue that the study's results are oversimplified and apply only to a small group of mostly White people during a specific time in history.