Well, like any study I'd need to see the methodology. It's a surprisingly difficult thing to find a solid number on, although at first glance it seems like it should be easy!
Here are some of her numbers:
Data Table PDF However the data seems contradictory to me or I'm not reading it correctly.
Total women surveyed: 123,272,000
Total of those that are married: 89,742,000
Still married to first spouse: 70.6%
Still married to second spouse: 65.3%
Still married to 3rd or more spouse: 59.4%
^^ I don't see how those percentages can coexist?
'
Maybe it's:
Of those women that married once - 70.6% remain married to their first husband
Of those women that married twice - 65.3% remain with their second husband
Of those women that married 3 (or more) times - 59.4% remain with that spouse.
That still looks like odd figures.
Perhaps it's basically saying:
1st marriages have a 30% divorce rate
2nd marriages have a 35% divorce rate
3rd and beyond have a 40% divorce rate
[actually I just linked and looked at this actual chart and those means (averages) don't really say much at all since the entire chart includes those single by divorce OR death of a spouse so over time it's going to average out the 2nd and 3rd marriages and make them seem just as successful while actually increasing the chances of divorce/death in first marriage. Basically it's a married versus single analysis at a single point in time. I think the 30.8% figure of "ever been divorced" is the best indicator that divorce isn't as prevalent as conventional wisdom tell us.]
I personally don't like hearing statistics because I'm ADD and I know my mind goes off on a tangent and down the rabbit hole about the realities of statistics and whether the number I've just been presented with is realistic, plausible or is it agenda laden, etc.
I know Dr. Harley likes to use the following statistics.
40% of marriages end in divorce (and little higher than the 30.8% number above).
20% of marriages end in permanent lifelong separation. They are still legally married but they hate each other and live away from each other and die away from each other.
20% of marriages stay legally married but are miserable and generally unhappy.
Only 20% of marriages stay together and are happy thus, only 20% of marriages are truly successful.
Now this study comes along and claims/states/presents findings that 4/5 are "happy". That's a big discrepancy. But that 4/5 are active and engaged participating Christian couples doesn't surprise me. I can certainly get on board with them being "happier" and more satisfied with marriage in general but a statistical jump from 20% to 80% seems a bit too rich for me not to be skeptical. How did they measure "happiness" and what "happiness" index did they use? I'm guessing they just asked people to characterize their "happiness" on a scale of 1-5 or 1-10 versus really measuring their relational happiness and satisfaction over time.