Whoops! This study says pregnancy is contagious among friends (so watch out!)
If it seems like everyone in your gang is suddenly, one after the other, getting pregnant – there might be a scientific reason for that.
Are you ready for this?
Pregnancy can be contagious.
Yup, it's true.
“A friend's childbearing positively influences an individual's risk of becoming a parent,” concluded the authors of a 2014 study published in the journal American Sociological Association.
For the massive study, researchers analyzed data on 1,720 women who participated in the National Longitudinal Study of Adolescent Health (ADD Health) in the United States from the mid-1990s to mid-2000s. Tracking female participants who were at least 15 years old in 1995 with home interviews throughout the next decade, the researchers saw that roughly half of the women had a child by the time the final interviews were conducted in 2008 or 2009.
As part of the interviews, the women in the study noted up to 10 “friendship ties,” which gave the researchers insight into the patterns among groups of friends as they aged.
And interestingly, what they found when focusing specifically on pairs of high school friends though later years, the researchers found there is a strong “contagion” element for planned pregnancy.
Of this "fertility influence" the researchers explains:
“We found this effect to be short-term and inverse U-shaped: an individual’s risk of childbearing starts increasing after a friend’s childbearing, reaches a peak around two years later, then decrease.”
Other studies have confirmed much of the same – there is a strong peer effect on fertility. In fact, according to a German study, the “risk” for a woman to get pregnant increases with every friend she has whose given birth within the past three years.
As for why this happens, researchers have three main theories:
Social learning: Women may be more inclined to embark on motherhood when they see a close friend navigate it successfully.
Social influence: Women may not want to feel “left behind” if their friends are collectively stepping into motherhood.
Cost-sharing: From more of a logistical standpoint, there are some financial perks if two friends know they can coordinate on activities and childcare.