For a few days, the media took a break from its relentless promotion of marriage and claimed something entirely different: the happiest people are not married with children, they are the single women who have no children.

Professor Paul Dolan made that claim at the Hay festival in Wales on May 25, 2019. He was sharing some of the findings from his new book, Happy Ever After. Apparently, he got an enthusiastic reaction from the audience. The word spread beyond the festival, and in news articles and personal essays, single women were being celebrated.

Unsurprisingly, other people did not take kindly to the idea that single women with no kids could be doing well, so the backlash began. On Twitter, an economist found data comparing currently married men and women, with and without children to their always-single counterparts — at one point in time. The single women with no kids were not the happiest.

If you have read anything I have written about this sort of thing in dozens of blog posts and articles and books, or if you are the kind of person who gets whats going on with these sorts of claims, even without any special training or instruction, then your b.s. detector is probably going off.

Heres the key problem:

A study comparing people who are currently married to people who are not married, at one point in time, and finding that the currently married people look better, cannotdefinitively show that they did better because they got married.

Ive discussed this in more detail elsewhere (see, especially, the article on 1-step debunking), but basically it is the classic problem that correlation is not causality, and then some. The added extra is that the currently married people are a select group. They do not include all the people who got married, hated it, and then divorced probably more than 40 percent.

Heres what people want to say when they think theyve found that married people are doing better, and why they cant say it

Think about this: What do people want you to conclude when they point to findings showing that currently married people are doing better than people who are not married? Sometimes they spell it out: Marriage is making people happier or healthier (or whatever the study is about). Therefore, if you get married, you will be happier or healthier, too.

You cant say that because the more sophisticated longitudinal studies (that follow the same people over time) do not show that. For example, 18 studies of happiness show that people who marry become no happier than they were when they were single, except occasionally for a brief increase in happiness early on. The best studies of health demonstrate that people become no healthier, or sometimes even a bit less healthy, after they marry than they were when they were single.

You also cant tell people that if they get married, they will get happier and healthier for another reason: if you get married, you may end up divorced or widowed. Some of the same longitudinal studies show that people who divorce or become widowed typically end up less happy and less healthy than they were when they were single.

But what about the studies showing that single people are doing better?

Some studies show that single people (who have never married) are doing better than married people. What should we make of them?

If they are studies comparing single people to currently married people at one point in time, the same cautions apply. We cannot know that the single people are doing better because they are single.

And yet, it is noteworthy when single people look better than currently married people, because the comparison is stacked against them. Remember, people who get married and dont like their marriage can leave. A very substantial number (probably more than 40 percent) choose to do so. The people left in the currently married group are the ones who did not leave. Basically, they are the people who got the most out of their marriages. They are a select group. They are not representative of what happens when you get married.

Now consider the single people. True, some may not like their single lives, and that is important. But they will stay single anyway, unless they can find someone to marry. They cannot leave their single life the way a married person can leave their spouse.

So when studies find that single people are doing better than currently married people, we dont know whether they are doing better because they are single. But it is a comparison that is biased against them. They are not being compared to everyone who ever married only to those who are currently married. When they come out ahead, it is a bit more impressive than when currently married people do.

Lifelong Single Women with No Kids: Best Evidence that They Are Doing Better than Other Women

I still dont have Paul Dolans book. (It is on its way.) In the meantime, the best evidence I know of that shows that single women with no kids are doing better than all the other women is from an Australian study of more than 10,000 women in their seventies. It is a cross-sectional study, so it is subject to all the qualifications I already described. Keep that in mind.

The fact that the women were all in their seventies means that the findings may not be generalizable to younger women. (And men were not included at all.) But according to all the scare stories, it is the single women with no children who are supposed to be most terrified of what will befall them as they grow old.

Ive discussed the results of the study in detail previously, so here I will just point to some highlights of the ways in which the lifelong single women with no children were doing better than:

  • Married women with children
  • Married women without children
  • Previously married women with children
  • Previously married women without children

The lifelong single women with no children:

  • Were less stressed
  • Were more optimistic
  • Had larger social networks
  • Were more likely to volunteer
  • Were less likely to be smokers
  • Had a heathier body mass index
  • Were less likely to be diagnosed with a major illness
  • Were more highly educated

What do these studies say about what you should do?

Big life decisions about matters such as staying single, getting married, or getting divorced are deeply personal. Research can provide you with information about general patterns, but all findings are based on averages across lots of people. There are always exceptions to the typical results. You may be one of them.

Even longitudinal studies need to be interpreted with caution. Suppose, for example, that some future study found that people who got married (all of them, not just the ones who stayed married) did better than they had when they were single, and continued to do better over time. That would be reasonably good evidence suggesting that getting married could be beneficial. (It is still not the gold standard of randomly assigning people to get married or stay single, but we cant do those studies.)

Nonetheless, that hypothetical study is based on people who chose to marry. They are different people than, say, people who are single at heart and live their best, most fulfilling and meaningful lives by being single. Just because a person who wants to marry benefits from doing so, does not mean that a person who embraces single life would do better if they got married.