Researchers followed 1,793 BT call-centre workers for six months and found that a one-point rise in weekly happiness was associated with roughly 12% higher sales productivity—not because employees worked longer, but because they converted more calls into sales.

Call-centre agents wearing headsets and working at computers in a bright office

“Happy workers are more productive” has the suspicious neatness of a sentence invented for a management presentation. It is agreeable, difficult to oppose and vague enough to survive ...