It may be true but not actionable. For example, some wives may be happy regardless of how much their partners bend over backwards to please them. Their partners are then more likely to have a happy life. Or, maybe your wife will be miserable no matter what you do. You're less likely to have a happy life. This is why I believe the most important step in vetting a spouse is to spend a long time with them first, the longer the better. How happy you both are isn't likely to change much after you get married.
This is logical thought. Relationships run on emotions. For most of history marriage's sole purpose is to create social security for women. That is really a problem, because once a service is provided, there is always a scope for improvement. If there is a crisis people are busy solving the crisis, in times of relative peace people think they should be optimising for a better deal. There is always a man better than you. Somebody is more healthy, wealthy and spends more on his wife, and you are continuously benchmarked against him.
Heck in most cases you might even be getting benchmarked against a fictional figure who exists only in her imaginations.
The more you do, more that fictional figure gets better than you, and you are expected jump over the bar she just raised. Sooner or later you will burnout and she will hate you for being weak compared to the hero that exists in her mind.
What I'm getting at is that, by adulthood, those behaviors are not easily changed, at least beyond temporarily. People know they'll live longer if they quit smoking, but despite the enormous benefits, it tends not to happen. I'm not saying it doesn't happen. I just think it's more realistic to go into a marriage with the expectation that the person you're marrying is not likely to change much.
