I recently came across a study I read years ago titled “Does marriage make people happy, or do happy people get married?”.
The answer is a little bit of both: if you are predisposed to happiness, then there is a higher likelihood you will choose to get married. When you do get married, your overall life satisfaction will climb, and even when you are not in a state of elevated satisfaction, you will have a “base” that is much higher than your singles days. Even more interesting, for marriages post-35, the gap in life satisfaction pre- and in-marriage is even greater. Better to get married at 42 than 22! [the study]