Frankly I doubt this is something we can get a good handle on by survey. How many folks are going to own up to the divorce being caused by their affair, or their sexual refusal, or their fetish? Those wronged by these things may also be reluctant to share those details – “We grew apart” is easier than “S/he would never have sex with me”.
Is sex a factor in 43% of divorces? I would think it’s a factor in most divorces to some degree or another. Most divorces have many factors, but in most situations, one or a few of these factors are so significant that the others are essentially unimportant. So the question is this – how often is sex a significant contributing factor to divorce?
When divorce follows adultery, clearly the adultery caused the divorce, right? Maybe not. While some folks are just too selfish, or too lacking in self-control, to avoid the chance of sex with someone else, I think most understand the potential marriage ending consequences of an affair. I suspect many affairs are sign that the person no longer cares about the marriage. Sometimes an affair is a signal to their spouse, or giving them a reason to file divorce. I doubt many affairs happen in solid marriages, so in some ways the affair is more a symptom than a cause.
What about men, and a growing number of women, who are sexually starved for many years? As deeply as this hurts, I doubt it directly causes many divorces. On the other hand, ongoing sexual frustration slowly kills a marriage, and as the couple drifts further and further apart divorce becomes more and more likely. An affair also becomes more likely – not directly due to a lack of sex, but more because of the lack of relationship that comes from a lack of sex.
So is sex a big factor in divorce? I think it is – but in a less than obvious way. I see sex as an act that brings a couple together. It builds their relationship, and binds them together. It makes them feel close, intimate, and connected. If divorce is weeds choking out a marriage, then sex is a very good weed killer. Sex won’t fix big problems, but it does smooth out and diminish a lot of things that would become big problems over time. Sex helps a marriage avoid getting to the point where being apart seems like a good idea. If this is the case, then sexual problems allow other marriage killing things to develop and grow. Sex is a potent marriage protector, and a lack of good sex means the marriage is less strong and more open to attack.
That, by the way, is why I talk about sex a good deal. Sex is not just a bonus in marriage, it’s important. Sex won’t save a marriage on the brink of divorce, but a good sex life can keep a marriage from being on the brink of divorce. More and/or better sex won’t improve all marriages, but less sex will hurt the vast majority of marriages.