This paper describes the findings from a new, and intrinsically interdisciplinary, literature on happiness and human well-being. The paper focuses on international evidence. We report the patterns in modern data; we discuss what has been persuasively established and what has not; we suggest paths for future research. Looking ahead, our instinct is that this social-science research avenue will gradually merge with a related literature -- from the medical, epidemiological, and biological sciences -- on biomarkers and health. Nevertheless, we expect that intellectual convergence to happen slowly.