It’s hard to say exactly when it happened, but it seems like every high school friend I have is either pregnant or has just had a baby. My Facebook newsfeed has transformed into a never-ending scroll of blurry sonograms, baby showers, and tired-but-happy-looking brand-new families of three. You’ll probably go through a period like this if you haven’t already, and a new study helps explain why.
Pregnancy spreads through a social network of female high school friends like a “contagion,” write the authors of the new paper, published today in American Sociological Review. The effect is seen soon after one friend gives birth, peaks after two years, and fades out soon afterwards, the authors write. As co-author Nicola Barban, a postdoctoral fellow in sociology at the University of Groningen in the Netherlands, said in the study’s press release:
“It takes time to have a child — because there is a natural period before conception and because the desire to have a child develops over time,” he said. “As a result, the effect of a friend giving birth is not immediate. If we had observed an immediate effect, we would have concluded that, rather than being influenced by each other, friends just decide to have children at the same time.”
The researchers used data from the National Longitudinal Study of Adolescent Health to track more than 1,700 American women from age 15 to 30. They focused the study on female high school friends, and they only included planned pregnancies of first children.
So why the pregnancies-in-bunches? The researchers have a couple of theories. First, people compare themselves to their friends. And with the help of Facebook and Instagram, of course, that social envy can now easily travel long distances. But there’s also a very practical reason to have friends at the same time as your high school buddies, especially if you’re still in touch: It’s great to have friends who are in the same stage of life as you. You can bond over stress about pregnancy and parenting, and, the researchers say, “it’s also easier for people to remain friends when they are experiencing parenthood at the same time.”
On a slightly disturbing note, the author of the press release noted that the study “shows that high school friends impact our lives well after graduation.” Yet another reason you will never truly escape high school.