What's the most important milestone in a relationship? Moving in together? Getting married? Having a baby?
According to a Stanford study, How Couples Meet and Stay Together, the most significant moment in a relationship isn't a special occasion, it doesn't necessarily involve champagne and perhaps doesn't get the recognition it deserves. Rather it is a day like any other that occurs somewhere in the 4th year of a relationship as the likelihood of a couple staying together becomes higher than the likelihood of them breaking up.
To study couple dissolution rates over time, Stanford implemented follow-up surveys one and two years after the main survey. Using the study's open dataset, we visualized the length of a relationship against the percentage of people reporting to have broken up since the survey was last conducted. The clear indication here is that 5 years is long enough to persuade most of us that our feelings towards our partners is more than infatuation.
After relationships reach their 5th anniversary, the percentage of surveyed people reporting to stay together becomes higher than those reporting to have broken up.
To zoom in on this potentially relationship defining trend, we took data for the first 10 years of relationships and plotted the chart again - this time hoping to find more detailed patterns.
The likelihood of a breakup jumps down as the second and again the third years of a relationship pass. But the fourth year of a couple's life is just as likely as the third to end in departure. It's only after a couple reaches the 5th year of their relationship that the likelihood of break up falls sharply.
The study's data suggests that this passage between years 4 and 5 of a relationship is a significant turning point. And sure enough, just as this time period lowers the probability that a relationship will end, we also see a change in regard to a more familiar milestone - marriage.
Couples are more likely to be married than not after 4 years in their relationship.
The percentage of surveyed people reporting to be married becomes higher than those not reporting to be married after 4 years of a relationship.
Taking a closer look at the specific data points recorded for the first 10 years of relationships, it's clear that this passage between years 4 and 5 is significant once more. The likelihood of a couple not being married falls sharply after reaching their 4th anniversary.
The probability of being married increases just as sharply after year 3 of a relationship and somewhere between its 4th and 5th anniversary, the probability of being married actually overtakes the probability of not being married.
We've also used the data in Stanford's study to investigate the ways in which couples meet and what defines a 'happy' relationship. Check out the investigation here.