Another Longitudinal Study of Satisfaction

One of the studies I described at length in Singled Out and have also mentioned here in this Living Single blog is a study of life satisfaction measured over time. In the dataset analyzed by Richard Lucas, more than 30,000 Germans were asked, once a year starting at age 16 at the youngest, to rate their overall satisfaction on a scale ranging from 0 (totally unhappy) to 10 (totally happy). Because the study has been ongoing now for more than two decades, it has been possible to see whether happiness changes as the same people get married, get divorced or widowed, or stay single.

In the most recent issue of the Journal of Marriage and Family, a similar study of a Dutch sample was reported. The authors (Judith Soons and colleagues) followed more than 5,500 people, starting at age 18 at the youngest, for up to about 18 years. Their measure of satisfaction (or subjective well-being) was the average of participants' ratings of four items, each answered on a 1 to 7 scale:
• "In most ways my life is close to my ideal"
• "The conditions of my life are excellent"
• "I am satisfied with my life"
• "So far I have gotten the important things I want in life"

In the rest of this post, I'll compare some of the main results from the two studies.

1 In both studies, the people who stayed single were on the happy/satisfied end of the scale for every year of the study.

The specifics: In the German study, the lifelong singles had happiness ratings averaging about 6.4 (on a 0 to 10 scale, with 5 as the midpoint). In the Dutch study, those who were single and without a partner (not married and not cohabiting) throughout the entire study (1987 through 2005) were also solidly on the satisfied end of the scale (an average of 5.0 on a 1 to 7 scale with 4 as the midpoint).

2. In both studies, people who married and stayed married became happier at first, then gradually became less happy over time. Probably the biggest difference between the two studies was that in the Dutch study, the initial gains in happiness diminished more slowly.

Here are the specifics. In the German study, people became about one-quarter of a point happier in the year surrounding their wedding day, compared to before they married. Within a few years, their happiness returned to what it was when they were single. In the Dutch study, people who entered a cohabiting union or a marriage became about one-half point happier than they were when they were unpartnered (a bigger increase than in the German study), and it took about a decade for their happiness to return to where it was before they moved in together or married.

3. In both studies, those who married and then divorced reported a substantial decrease in satisfaction. Levels of happiness right after the divorce dipped below the lowest level of happiness ever reported by those who stayed single. Little by little, those whose relationships dissolved do regain happiness over time.

If the two studies were totally comparable, you could say that lifelong singles in both countries are, on the average, clearly on the happy end of the scale every year of their lives; that those who divorce experience lower levels of happiness, at least for a while, than continuously single people ever do; and that people who marry and stay married become happier at first but then, little by little, become less happy over time. The main difference is that in the Dutch group, that initial increase in happiness declines much more slowly than it does in the German group. (If you don't want to hear any qualifiers, you can stop reading here.)

However, there are ways in which the studies are not entirely the same (in addition to those I already described). If you were to wander deep into the statistical weeds, you would find that the two studies differ in analytic strategies in ways that could have had implications for the findings. Here are a few examples you can understand without advanced training in statistics. First, the abstract of the Dutch study says that "the well-being of never-married and never-cohabiting young adults decreased slowly over time." But if you read the results section closely, you will see that once you "control for" age, there is no decrease over time. (I explained "controlling for" in this previous post.) Second, Table 1 of the Dutch study indicates that 14% of the "single" people had experienced a break-up of a cohabitation or marriage in the past. Those 14% are single only in the sense of being currently single; they are not lifelong singles. Other analyses do seem to differentiate the lifelong singles but then those people are not the same as the ones in the table. Like I said, deep in the weeds.