There’s a growing body of evidence that shows the relationship between age and happiness.
The theory is called the Happiness U Curve, and it shows a dip in happiness in middle age, but shows a rise later in life.
It cuts across countries and ethnic groups, and has been reported even in primates.
Jonathan Rauch is a contributing editor of National Journal and The Atlantic, and a visiting scholar at the Brookings Institution.
He wrote about the Happiness U Curve, and his own experience with it for the Atlantic.