'Nun Study' lessons: Cheerful sisters live longer than unhappy nuns

A study on nuns reveals some important messages about being truly happy.

In the 1930s, some American nuns were required to write short autobiographies following their final vows. Decades later, their essays would become part of an important study of positive psychology.

It’s likely that the task was originally designed to help with determining the career paths of the nuns, and yet the writings would go on to suggest an important link between the kind of emotive language we use and the degree of our longevity.