Another time I wish I kept a master file on studies I have read or read about...

The ‘happiest’ people? Those that are happily married (an apparent small subset of all married people)

The next ‘happiest’ - long term singles

In between are all the flavors of ‘in a relationship’, ‘cohabiting’, etc...

Least happy (by far) - the multiply married.

For the multiply married, each subsequent marriage is less satisfactory, more fragile, and shorter lived...