Since then, interest in the U-bend has been growing. Its effect on happiness is significant—about half as much, from the nadir of middle age to the elderly peak, as that of unemployment. It appears all over the world. David Blanchflower, professor of economics at Dartmouth College, and Mr Oswald looked at the figures for 72 countries. The nadir varies among countries—Ukrainians, at the top of the range, are at their most miserable at 62, and Swiss, at the bottom, at 35—but in the great majority of countries people are at their unhappiest in their 40s and early 50s. The global average is 46.
The U-bend shows up in studies not just of global well-being but also of hedonic or emotional well-being. One paper, published this year by Arthur Stone, Joseph Schwartz and Joan Broderick of Stony Brook University, and Angus Deaton of Princeton, breaks well-being down into positive and negative feelings and looks at how the experience of those emotions varies through life. Enjoyment and happiness dip in middle age, then pick up; stress rises during the early 20s, then falls sharply; worry peaks in middle age, and falls sharply thereafter; anger declines throughout life; sadness rises slightly in middle age, and falls thereafter.