In a 2017 study published in the prestigious journal Social Forces, sociologist Matthijs Kalmijn makes a valuable contribution to research probing the health effects associated with marriage. His study, “The Ambiguous Link between Marriage and Health: A Dynamic Reanalysis of Loss and Gain Effects,” is a solid study with an unusual approach to the topic. Unlike most research in this field, it takes into account that people are at risk for divorce once they marry, and finds that the health risks of a possible divorce are larger than the health benefits of marriage. But it is also a study that can easily be misinterpreted to claim that a large body of research documenting the positive, protective health effects of marriage is bunk. That is what a New York Times columnist did when she got a hold of the study.
But first, a brief summary. Kalmijn used a large, nationally-representative sample of households in Switzerland followed for 16 years. He looked at marital transitions – marriages and divorces – to examine how entrances into, and exits out of, marriage impacted mental and physical health. He concludes that health gains from entry into marriage are small and do not accumulate over time (given high rates of premarital cohabitation, it’s not surprising that marriage entrance gains now are muted). He finds, however, that health losses from exiting marriage (i.e., divorce) are about three times larger than health benefits gained from marriage, although he finds substantial adjustment and recovery from the negative health effects of divorce over time. Also, he finds that the health effects are strongest for reports of general life satisfaction, more moderate for mental health (i.e., depression), and weak or absent for physical health (self-reported general health).
Kalmijn does not dismiss the extensive body of research that documents how marriage serves as a protective factor for health; rather, he questions how big those effects are. Kalmijn hypothesized that gains and losses should be larger, and should accumulate, if marriage is a clear health protective factor. Nevertheless, as a careful scientist, he is sensitive to the limitations of his study. First, he studied Swiss adults, while most similar research has been done with American samples. He acknowledges that the Swiss are much more likely than Americans to say marriage is an outdated institution and marriage “has a higher status and possibly a stronger protective function in the United States than in Europe.” Moreover, he notes that Switzerland has a low divorce rate and a large social safety net, so divorce there does not hold the same economic or even social consequences as it does in the United States. Thus, the health benefits of marriage would likely be less in Switzerland than in the United States.
In addition, Kalmijn removed older individuals (65+) from his study: “We deliberately abstained from analyzing the elderly, since this introduces different conceptual issues (e.g., loneliness, widowhood) and makes it more difficult to compare entry and exit” to marriage. But, as he acknowledges, the health benefits of marriage may be greatest in old age. Thus, the age exclusion likely muted the protective health effects in his study. Kalmijn also notes that some of his key measures had limitations. For instance, the single-item measure of depression (how often participants had “negative feelings such as feeling disheartened, desperate, anxious, or depressed”) available in his data set likely is not as sensitive as standardized, multi-item scales, so associations between marriage and health could be underestimated. Finally, he admits that the health measures in the data set asked for self-reports of general health rather than reports of specific health-risk behaviors (e.g., smoking, drinking, drug use), which other studies have often used, finding significant protective effects for marriage.
But perhaps the most important distinction between Kalmijn’s study and its peers – a subtle difference casual readers might miss – is that Kalmijn estimates the total health effects of marriage differently than other researchers:
Entering marriage goes with the risk of divorce, so that the total [health] effect of marriage is a function of the effect of marriage entry [which he found to be small and non-accumulating], the effect of marriage exit [which he found to be more robust], and the risk of divorce [which is substantially lower in Switzerland than in the United States].
Kalmijn makes a good point here. Any health gains from marriage must be weighed against the health losses associated with the potential for divorce. So, in societies with high divorce rates, the negative health effects of divorce are subtracted from the positive health effects of marriage to mute the overall, societal benefits of marriage.
This does not so much contradict a large body of research as make a noteworthy distinction: Those who marry take on the risk of divorce, potentially ending up worse than where they started because divorces have large negative health consequences, and entrance into marriage has modest health benefits. But this does not take away from the protective benefits of marriage for those who remain married. When a marriage succeeds, those health benefits are noteworthy; when it fails, the health benefits of marriage are absent.
This isn’t too hard to grasp, but it can be misinterpreted, as was evident in Bella DePaulo’s New York Times op-ed. DePaulo – who wrote the recent, popular book, Singled Out: How Singles Are Stereotyped, Stigmatized and Ignored, and Still Live Happily After – drafts the study’s findings into her cause of empowering single people who, she says, are victims of discrimination in a marriage-crazy culture:
Free of the myth that marriage is a magical potion, we can pursue the life paths that suit us best. Marriage is still there for those who want it. But now people who prefer to live single can come out of the shadows.
Marriage is a lifestyle choice, the author suggests, one free of any implications for our individual and collective health. Curiously, DePallo employs the following analogy to the Kalmijn study to try to make her point that marriage’s health benefits are overrated:
Imagine that a pharmaceutical company, in testing a new drug, found that 40 percent of the people on the drug [roughly equivalent to the divorce rate] refused to keep taking it. Then imagine that the company simply ignored those people, or included them with the people who never took the drug. They might then find that people currently on the drug are doing better than people not on the drug. But would you take a drug based on that argument?
Well, yes. The drug works for those who take it as prescribed; it does not work for those who drop out. If we want to know what the effect of the drug will be in a given population, then yes, we need to take account of the reality that 40 percent will not take it as prescribed, so the population health benefits will be attenuated. But if we want to know if the drug is effective for individuals when taken as prescribed, then we would exclude those who didn’t take it. Kalmijn’s study approaches the question of the protective health benefits of marriage from a population standpoint, appropriately taking account of the negative health effects of those who drop out (i.e, divorce). As a result, the health benefits of marriage are muted in the population when there are high rates of divorce. But this does not diminish the salutary health benefits of marriage for those who take their marital medicine as prescribed.
Finally, we should recall that science is a team sport and that the replication and accumulation of research on a topic is more authoritative than any single study. So, it is important to look at the full body of research in this area, not just one study, even one like Kalmijn’s that makes a valuable clarification. There are hundreds of studies in this area, systematically reviewed in a handful of meta-analytic studies over the past decade, that make a solid case for the protective health benefits of marriage. For instance, one team of meta-analytic researchers examined nearly 100 studies covering more than 500 million people, looking at mortality risks of never-married singles versus currently-married individuals. They found that singles had a 24 percent higher mortality rate than marrieds (using multivariate-adjusted hazard ratios with a high subjective quality rating). Similarly, a meta-analysis comparing mortality rates of married and divorced individuals in more than 100 studies covering more than 600 million individuals in 24 countries found that divorced individuals had a 30 percent higher mortality (adjusted) risk compared to married individuals, and the risk was significantly higher for men than women, as well as for younger participants than older individuals.
A full reading of the research on marriage and health affirms the protective health benefits of a successful marriage. Kalmijn’s study alerts us that the health risks of a failed marriage are substantial, too. Thus, to reap the societal benefits of marriage, we need lower divorce rates and stronger marriages. This helps to explain why public policies and initiatives in several countries, most notably the United States, are being targeted in this direction.