A play on Andy Warhol’s Marilyn Monroe screen prints, this work reflects on the nature of happiness and how it changes over one’s lifetime. Happiness is a topic of growing interest in research and public policy. In general, people are happy when young, have a mid-life slump, and are then happiest in old age. But there are significant differences by country. Look at the charts below and compare them with the smiles on the smiley faces.