Revealing:
Mentions of God or religion - ZERO.
It may have been included in the data, but not in this review; regardless, other studies have often shown that a couple's religious background in common and a healthy relationship with a religious community is a statistically positive benefit to marriage.
The study director, Harvard psychologist George Vaillant, did write books titled "Spiritual Evolution : A scientific defense of faith" and "Spiritual Evolution: How We Are Wired for Faith, Hope, and Love". Religion is often omitted because any mention of it completely turns off city slickers from the subject being discussed.
The study is clearly about relationships. Not saying someone’s religon and/or relationship with god isn’t important. For many, it is. The clearest indicator of success in this study was a child’s relationship with his parents, especially his father.
I will concede that a thorough Christian upbring (I assume most of these men were Christian with maybe a few being Jewish based on the time frame of the study) will help a man realize the importance of his fatherly duties. However, I’m sure there were many cold yet devout dads in the study too.
Full disclosure, I was raised in a non-religous household. The only time I was in church was the occasional wedding or funeral. However, I had very loving parents. My dad was thoroughly involved in my life in every respect-coaching my sports teams, encouraging my talents, lots of vacations, advice, etc. Same with my mom. I have close relationships with my siblings and their children. Frequent fun family gatherings, etc. No religous input of any kind. I’m not knocking religon, just saying you can thrive without it too.
The cycle continues for my siblings and myself. Successful careers, marriages, lots of children. Not rocket science, but a loving family is key. Glad to see that verified by 70+ years of data.