Our childbearing decisions – whether we have children, when, and how many – are influenced by the decisions our peers make and the examples we see around us in everyday life.
This is an effect we intuitively understand. A photo of your co-worker’s sweet baby might make you wonder if you might like one of your own. Spending time with a sibling who isn’t enjoying being a mum or dad might make you less likely to want to be a parent yourself. It isn’t just people you know in real life who can influence your fertility; cultural outputs like TV and books matter too.
In this way, being a parent can be socially and culturally transmitted: a ‘meme’ in the sense that Richard Dawkins originally used the term. That fertility, like many other elements of human life, is socially or memetically influenced has tremendous consequences for policies that want to make it easier to have children. And also for understanding why it can be so difficult for a country with low birth rates to increase them.
Friends and family
Simply put, the more people you know who have children, particularly peers, friends and siblings, the more likely you are to have a child yourself. Interestingly, the effect is at its strongest if the friend or family member’s child is aged under 3, and potentially negligible after that. The effect works the other way too: the fewer peers you know with children, the less likely you are to become a parent.
Even someone we might be much less close to, like a co-worker, can influence the decisions we make around parenthood. A 2024 study looked at data from 11 million Italians to investigate the peer effects of people’s fertility decisions on their colleagues. They found that a 1 percentage-point decrease in average co-worker fertility led to a reduction in the individual probability of having a child of 0.3 to 0.4 percentage points.
TV and fertility
It isn’t just those we know personally who might influence our fertility decisions – perfect strangers and fictional people matter too.
MTV’s 16 and Pregnant was a reality TV show that aired from 2009 to 2014. Described by one NYT writer as “showcasing the grim, hard work of single mothering”, each episode followed a pregnant teen from a few months into her pregnancy until her child was a few months old.
The National Campaign to Prevent Teen and Unplanned Pregnancy attributed a decrease in teenage pregnancy in 2009 directly to the airing of 16 and Pregnant. And in 2014, a widely cited paper co-authored by Melissa Kearney found that the show had indeed led to a 4.3% reduction in teen births between 2009 and 2010 (it’s worth noting that teenage pregnancy in the US was in general decline already).
Another example comes from Brazil. Telenovelas, a type of TV soap opera, often feature small families. This is in part because it makes the plot more manageable for showrunners and writers.
A 2012 paper identified a clear ‘telenovela effect’ on fertility: the more Brazilian women were exposed to telenovelas, the fewer children they had. A subsequent Atlantic article hailed telenovelas for encouraging smaller families and stopping a “population boom in the developing world [that] threatens to devour the world's resources”. Other studies have also found a link between exposure to TV and reduced fertility, including in India, Pakistan and South Korea.
These studies indicate that western TV shows and films, in depicting small families, are helping to instil a smaller family habit in the non-Western world and contributing to declining birth rates in those countries.
A self-perpetuating culture of parenthood
If you are not a parent, it can be hard to imagine what having a baby might be like, or how you might manage new expenses like nappies and daycare. In countries where fertility has fallen very low, young people are less likely to see or interact with families with children. Living in a society like this helps to create a self-perpetuating culture of lower fertility.
An example of one such society is South Korea. South Korea’s slide into ultra-low fertility was initiated by a wide-ranging and long-lasting antinatal policy programme introduced in the 1960s. Though that programme ended in the 1990s, the small family norm created by this top-down policy has been re-signalled between citizens again and again and again, creating a norm that today actively works against the South Korean government’s efforts to increase the birth rate. Only 28 percent of unmarried South Koreans aged 19-49 say they want children. By comparison, 51 percent of childless Americans aged 18 to 34 do.
But peer effects can also work to strengthen the effects of pro-child policies. As Boom has covered, the employees of Taiwan Semiconductor Manufacturing Co (TSMC) are responsible for 1.8% of all babies born in Taiwan, even though they make up only 0.3% of Taiwan’s population. In 2023, one in every fifty Taiwanese babies born was a TSMC baby.
This could be not only because TSMC staff have well-paid jobs and work in a company with parent-friendly policies that actively make having a child easier, but also because these policies have created a pocket of pro-parenthood culture in ultra-low fertility Taiwan.

TSMC workers are surrounded by peers who demonstrate that having children is achievable – this has the effect of encouraging parenthood and creating a self-perpetuating culture of higher fertility. A similar effect is also likely at work in South Tyrol, Italy’s highest fertility region.
Even in China, where the extremely oppressive one-child policy enforced a low fertility norm for decades, there is evidence for positive peer effects that mean women are more likely to have children when peers in their community do.
How policy and culture cooperate
There is a temptation when discussing pro-child policies to talk about ‘culture’ as existing in a separate sphere that policy cannot touch. But the socially influenced nature of fertility means that culture can organically work to strengthen the effects of pro-child policies.
By successfully making it easier for one person to start their family, policymakers sparks off a chain reaction of other pro-parent effects. That person makes it easier for others to become a parent simply by being one themselves. In this way, pro-parent policies ripple across society, reaching more and more people.
Conclusion
The insight that the decisions we make around parenthood are socially influenced is important in understanding the factors at play in both lower and higher fertility countries and regions.
It’s also vital in thinking about policy and culture as cooperative partners when we consider how we can make it easier to have children, for everyone.
Finally and importantly, a self-perpetuating culture of parenthood does not mean socially pressuring people who don’t want to be parents to have children. Rather, it means creating communities where those who do want children can see that becoming a parent is a choice they can make.
Phoebe
With thanks to Phoebe Hunt for her research assistance.