Does natural family planning decrease divorce rates?

According to Dr. Janet Smith's lecture "Contraception Why Not" the Family of the Americas Foundation performed a study regarding rates of divorce and the use of Natural Family Planning techniques (as opposed to oral contraception, sterilization, etc. ). The statistic of 5% divorce rate for couples using NFP is what I commonly hear and read.

Perhaps this is why divorce rates for NFP users are between 1/10 and 1/25 of the overall divorce rate in the United States in the 90s.4 Indeed, a study conducted by the Family of Americas Foundation found only 16 women ever divorced among 505 NFP users, a rate of 3.6%!5

Link to the study: [http://familiadelasamericas.org/inc/data/divorce_study_eng_wilson.pdf] According to the text of the study, this is the first study of it's kind. Was it so conclusive that it was also the last study of its kind? Does Natural Family Planning really dramatically reduce the chance of a couple to get divorced? Here's what the USCCB (United States Council of Catholic Bishops says the correct way to do the study would be:

if a researcher wanted to determine whether there is a difference in divorce rates among married couples who use NFP versus couples who use oral contraception, the study would be designed to track first time NFP and first time oral contraception users over a 10 to 20 year period. But what if a researcher did not have the time or money to track couples over a long period of time but still wanted to investigate the same issue? A "cross sectional" longitudinal study could be conducted instead. To do this study a large sample of married couples from NFP centers that have records from the 1970s and early 1980s would be needed. Next, a comparison of that data with a large sample of married couples who attended family planning clinics to obtain oral contraception in the same time period would have to be done. Once large enough samples are obtained from each grouping, an interview (by phone, in person or through mail) of the participants would have to be conducted in order to determine which of the couples divorced and the frequency of doing so.

Is that sufficient, does the Family of the Americas Foundation even come close? Divorce rates among Catholics (who make up the majority of the study) have been shown to be similar to other sects. An easy assumption is that this study just proves that faithful Catholics are far less likely to wind up divorced, but that should have no bearing on the question. But if correlation doesn't imply causation, does that assumption even have any merit?

I would have to say that correlation is not causation. Maybe those who practiced NFP were just that more comfortable in their relationship, and less likely to divorce. As opposed to those who went out of their way to prevent pregnancy. Maybe there's deeper problems in the marriage which is the reason many people use contraceptives. Once you have kids, divorces are much more difficult.

I’d just like to point out one tidbit, namely that NFP doesn’t work. So this study is comparing apples with oranges: namely, divorce rate among people who use effective contraception, and those that don’t, but think they do. I can see several ways how this might skew the results of the comparison … for instance, unexpectedly being settled with a child.

@Konrad Or another correlation: People using NFP are more likely to be deeply religious (staunch Catholics will not use condoms or the pill). In these circles, divorce is also something that is frowned upon, which means that these people are more likely to remain in a damaging/unhappy relationship where others would long since have gotten a divorce.

3 Answers 3

Looks like I was beaten to the punch, but there are a lot of issues here.

1. First, as Kibbee said in the comments, this is a whole lot of correlation, not necessarily causation. That should be enough.
2. This is also, to put it delicately, a very biased study (if you want to even call it a study). Right off the bat, just from the name of the organization, you can see that they obviously had a goal in mind when publishing this. From that alone, I'm not at all convinced that they're not skewing data towards their goals as much as possible. But that position is further reinforced in the very first paragraph (emphasis mine):

In contrast, couples who use artificial methods of birth control seem to experience disturbing spiritual, and psychological as well as physical risks to their body and soul.

Artificial methods do not encourage intimate communication between spouses as they transfer the burden of responsibility primarily on the woman 1 . Artificial birth control places an artificial barrier between husband and wife and limits the most intense physical expression of human love. Such methods facilitate the couple’s use and misuse of each other rendering them unable to fully appreciate the gift of their sexuality.

505 women returned useable completed questionnaires to an independent investigator retained by Family of the Americas Foundation to provide data entry and descriptive statistical analysis. The survey achieved a 74% response rate. Sampling for the NFP study was nonrandom, although the investigator did attempt to generate a representative sample of women in the U.S. who practice NFP. 1

The NFP respondents had taken instruction in Natural Family Planning at least three to over ten years ago. 92% of the women were White, 6% Hispanic and the remaining 2% Other.

There are just so many things wrong here, that any result they come up with should not be taken at all seriously. They've got an agenda, they most likely had a hypothesis they were out to prove, they're introducing opinion into what should at least try to be a scientific paper, they're not sampling randomly, they're only taking from their own participant pool, and the participant pool itself was demographically skewed.

Did they look at age? Income? The number of years a couple had been together/had been married? If the couple had lived together before getting married? If they had already had kids or not before getting married? If they had already had kids or not before getting divorced? If so, how many? This is all just off the top of my head.

So no, I sincerely doubt Natural Family Planning dramatically reduces the chance of a divorce.

Edit: Responding to the modified parts of your question. I wasn't sure what the USCCB was, but Googling it led me to the United States Conference of Catholic Bishops, so I'm assuming that's what you're referring to. The quote you've posted (seeing where you got it from would be nice) is a much better track to take, but as has been said, FAF isn't really approaching that at all. Think about all the questions I asked at the end of my original answer, and whether they (and others) are being addressed.

As far as the assumption you make that the study proves that faithful Catholics are less likely to be divorced. well. that's really quite an assumption. What defines a Catholic as faithful? That the Church condemns divorce and so they'd never do it? Were all the people in FAF's study part of that group? Is that really "faith"? I could just as easily assume that all the study proves is that white people are far less likely to wind up divorced. When you get into subjective land, it's tough to get out. So no, that assumption really doesn't have much merit either.