Harvard has been running longitudinal studies for several decades:

* https://en.wikipedia.org/wiki/Grant_Study

and their findings lean towards good relationships with family and friends are highly correlation with happiness, health, and many aspects of financial success. The released a book summarizing many results a few years ago:

* https://www.goodreads.com/book/show/61273746-the-good-life

* https://archive.is/https://www.theatlantic.com/ideas/archive...