Why pregnant women start to see other pregnant women everywhere

As I meandered through the farmers market, picking out the perfect produce to nourish my blueberry-sized baby in utero, I noticed something peculiar: pregnant women and moms with newborns were everywhere. Bellies at all stages of bloom squeezed between the tables, the lineup at the food truck was like a lookbook of baby carriers and the crowd at the music tent looked like everyone was there to see the Wiggles. How odd, I thought, that the place I used to meet my girlfriends for samples of cider and soft cheese had become a mommy mecca. And it didn’t stop there. In the nine months I was pregnant, I saw more expectant moms than I had in my entire life. Or at least I thought I did.

Turns out, my mind may have just been playing tricks on me.

“When something is on your mind, you start to notice it more than you did before,” says Nicholas Rule, an associate professor of psychology at the University of Toronto and Canada Research Chair in Social Perception and Cognition. “You’re unconsciously looking for it and you hadn’t been before.”

This is known as the frequency illusion, or the Baader-Meinhof phenomenon, and it occurs through two psychological processes: selective attention and confirmation bias. Selective attention means you’re hyper-focused on baby-related matters and overlook everything else, so you take notice of other pregnant women but wouldn’t give an attractive individual a second glance. Confirmation bias leads you to assume that every sighting of an expectant mom is further proof that there’s going to be a baby boom.

“It’s not that there necessarily are more pregnant women, but rather that all of a sudden you’re attuned to it because you’re thinking about your pregnancy,” Rule says. “It’s hard not to think about it; because of all the physical changes, you’re constantly aware.”

But the frequency illusion may not be entirely to blame, Rule says, and there are some good reasons why you may actually cross paths with more pregnant women when you’re expecting. For example, there are a number of obvious places that attract moms-to-be—prenatal classes, baby boutiques and midwifery offices—so you’re likely to spot each other in the bathrooms in the area.

Also, people who are starting families tend to congregate in certain neighbourhoods because they’re all drawn to the same things: parks, good schools, a community centre. “When young people move into an area, they encourage their friends to come because it creates a huge support system,” says Toronto real estate agent Josie Stern. “It’s word of mouth, and it spreads like wildfire.”

Pregnancy itself can spread like wildfire among friends, another possible explanation for seeing a steady stream of cute “we’re expecting” announcements on your social media feeds. This so-called “social contagion” happens with other major life events, too. “You tend to find that everyone is getting married at the same time, everyone is having kids at the same time,” Rule says. “Anecdotally, people can feel left out when all of their friends seem to be having families and they’re not.”

A 2014 study published in the journal American Sociological Review found that when a woman’s friend has a baby, her likelihood of becoming a parent starts increasing, peaking two years after her friend gave birth, and then decreasing. The authors suggest pregnancy is contagious because women compare themselves to their friends and want to share the parenting journey with them, so they can learn from and support each other. “We assume that having friends they can share their experiences with as parents may reduce the uncertainty associated with parenthood,” they write. “Synchronizing childbearing with friends may reduce the risk of being left behind by friends who already have a child.”

However, Rule points out, social contagion may only be part of the puzzle.

“There’s a relatively narrow window of time in which one is optimized to have children,” he says. “It seems like all of a sudden, everyone is having a child around 30, 32, but it’s really just a clustering because that’s when people tend to have children. I think social contagion facilitates it, yet there’s a reality there.”

When my mom friends started getting pregnant with baby number two, the idea was planted in my mind, and I soon followed suit, getting a positive pregnancy test just days after my eldest turned two.

Now that my youngest child has entered toddlerhood, I rarely see (or notice?) pregnant women anymore. But when my husband and I started shopping for a minivan, I saw them everywhere. While there wasn’t a baby boom after all, there certainly was a boom in black minivan sales—I’ve tried to get into the wrong one twice.

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