Below are the weblinks from the endnotes in Sex Purpose Love with short descriptions were applicable:
2. Social relationships—both quantity and quality—affect mental health, health behavior, physical health, and mortality risk.
Happiness and health aren’t a result of wealth, fame or working hard, but come instead from the quality of our relationships.
People with a sense of purpose had a 15 percent lower risk of death, compared with those who said they were more or less aimless