With social norms constantly in flux—remember Crocs?—choosing friends may be even more important than we realized. Social scientists have shown that your friends—and the standards you set for each other—influence not only your choice of footwear but practically every aspect of your life, from your politics to your marital status to your eating, drinking, and drug-taking habits. A new study in the June American Sociological Review adds another behavior to that list: getting pregnant.
In this study, Nicoletta Balbo, a postdoctoral fellow at Bocconi University in Italy, and Nicola Barban, a Dutch sociologist at the University of Groningen, find that if a woman’s high school friend becomes pregnant, the chance that she will have a baby herself increases, peaking two years after the birth of her friend’s baby. The impact of high school friends’ pregnancies appears to be even stronger and long-lasting than the effect of sisters’ pregnancies—which begins to decline just a year after the sibling’s baby is born. “In today’s individualized societies, friends may be equally or more important than siblings and other family members,” write the authors. Balbo and Barban rely on data from a longitudinal study that tracked a nationally representative sample of more than 1,700 American women from adolescence through early adulthood, over four “waves” of interviews, ranging from starting when the subjects were in seventh through twelfth grade and ending when the respondents were in their mid-20s to early-30s. To control for socioeconomic factors, Barban and Balbo compared respondents’ behavior not only to people they continued to identify as friends in follow-up surveys years after leaving high school, but also to a group they termed “peers”—high school classmates who resembled respondents in geography, income, and education but never listed each other as friends. The 820 pregnancies within the sample resembled the population at large: Just under half—47 percent—were unintentional, and the median age at first pregnancy was 27. (Balbo and Barban looked only at pregnancies that were planned.)
“We believe there are three possible explanations,” Balbo told the American Sociological Association. “First, people compare themselves to their friends. Being surrounded by friends who are new parents makes people feel pressure to have kids as well. Second, friends are an important learning source. Becoming a parent is a radical change. By observing their friends, people learn how to fulfill this new role. Lastly, having children at the same time as friends may bring about many advantages—friends can share the childbearing experience and thus reduce the stresses associated with pregnancy and childrearing. It’s also easier for people to remain friends when they are experiencing parenthood at the same time.”