Health 6 min read
Smartphones arrived just before the US fertility rate plunged. One study says it’s a direct cause
By
Deidre McPhillips
3 hr ago
PUBLISHED Jun 12, 2026, 7:00 AM ET
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The smartphone may have become a “substitute” for physical contact and in-person human interaction, the researchers said.
Anna Barclay/Getty Images
Summary
- A new study links the introduction of smartphones to a sharp drop in US fertility rates between 2007 and 2011.
- Researchers found that birth rates fell more in counties where more than 90% of residents had early iPhone access, especially among teenagers and women in their 20s.
- Other experts remain skeptical, noting that fertility has declined for decades and pointing to factors like expanded contraception access.
AI-generated summary was reviewed by a CNN editor.
The US fertility rate has been trending down for decades, leaving researchers and policymakers searching for causes that may help pinpoint solutions. There have been all kinds of theories, including soaring costs of childcare, the rise of birth control and even the role of car seat regulations.
A new paper offers a provocative culprit in a succinct package: the smartphone. But some other researchers are skeptical that this single factor could play such an outsized role in a much longer-term trend.
2007 marked a particularly significant “inflection point” in the US fertility rate, said Caitlin Myers, an economist with Middlebury College and the National Bureau of Economic Research, who is the lead author on the new paper.
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The Great Recession started at the end of the year, just a few months after Apple started rolling out the iPhone in the US – the first modern smartphone.
“We initially all just assumed it was the global recession. Births have long been known to be pro-cyclical, and so the conventional wisdom was they’ll come back up,” she said. “Then we had a baby-less recovery.”
In the years since, Myers said, she would often raise the topic of “iGen” — a name for the first generation to grow up entirely in a world with smartphones — around the dinner table and wonder about the drop in so-called risky behaviors in this group, who tend to have less sex and use fewer substances.
Her stepson, Ezekiel Hooper, also noticed that his younger siblings had very different relationships than he did, with much more social interaction happening though screens than in person — interactions that physically created “no chance of having a kid,” he said.
Hooper started looking into this connection between smartphones and the fertility rate for his senior thesis while studying at Middlebury a couple years ago, and he co-authored the working paper that was published last week.
In it, he and Myers tracked the spread of AT&T mobile broadband – which was at first the only network the iPhone was available on — and compared the change in fertility rate between 2007 and 2011 with the share of the population living with access to the network.
Apple CEO Steve Jobs introduces the first iPhone at the MacWorld Conference in San Francisco on January 9, 2007.
Paul Sakuma/AP
They found that in counties where more than 90% of residents had early smartphone access, the fertility rate fell significantly more than it did in counties where less than 10% of residents had network coverage.
The difference was sharpest among teens; The birth rate among 15- to 19-year-olds fell about 26% between 2007 and 2011 in counties with broad smartphone access, compared with a 14% drop in counties with limited smartphone access.
For women in their 20s, the birth rate fell 15% in counties with broad access, compared with 10% in those with limited access. And for women in their 30s, the birth rate fell slightly in counties with broad access, while it rose in other counties.
Early 3G coverage varied widely across the US
Early 3G coverage varied widely across the US
Denser urban areas were among the first to have broader access.
Share of population in AT&T 3G coverage area, Fall 2010
1%10%30%60%90%
Use the arrow keys ↑ ↓ ← → to navigate through the map regions.
Source: National Bureau of Economic ResearchGraphic:Deidre McPhillips, CNN
Overall, the researchers estimate that early diffusion of the iPhone caused between a third and a half of the decline in the general US fertility rate between 2007 and 2011.
The new study can’t explain exactly why smartphones would drive fertility rates down, but the researchers theorize that it may be related to ways the technology has shifted our time and attention — particularly in ways that would make it less likely to have sex and lead to a pregnancy.
Drops in unintended births to young people are a key factor in the broader decline in fertility rate in the US, the researchers say. And, in some ways, the smartphone has interrupted ways that can lead to an unintended pregnancy.
The smartphone may have become a “substitute” for physical contact and in-person human interaction, Hooper said.
“Instead of looking to somebody else for that interaction, they might be looking to online pornography,” he said. “Maybe instead of going out and just having those physical interactions with their friends and their peers, they’re having those interactions through their phone instead.”
In the early days of 3G, US counties with broader coverage had larger declines in birth rate
In the early days of 3G, US counties with broader coverage had larger declines in birth rate
The decline was most significant among teens living in counties with more than 90% mobile broadband coverage.
Change in birth rate from 2007 to 2011, by age group
Three groups of bar charts show that birth rates declined significantly among teenagers and among people in their 20s between 2007 and 2011, especially in US counties where more than 90% of the population had access to early 3G from AT&T. Birth rates dropped 26% for teens and 14.6% for people in their 20s in these counties.
<10% of population in 3G coverage area
10-90% in coverage area
90% in coverage area
15-19
20-29
30-39
−20−200%0%
15-19
20-29
30-39
15-19
20-29
30-39
Note: Mobile broadband coverage based on AT&T's 3G network in Fall 2010.
Source: National Bureau of Economic ResearchGraphic:Deidre McPhillips, CNN
A long history of declining fertility
Some other experts, who are focused less on the economics of fertility and more on the social and health aspects, agree that smartphones have played a role in changing relationship patterns that can lead to lower fertility rates — but they say the broader context matters.
“It’s true that people are marrying later, partnering later, and spending less of adulthood in stable relationships, and smartphones may contribute to those trends. But they are occurring alongside major changes in housing costs, education, labor markets, gender norms, and social life,” Dr. Alison Gemmill, an associate professor of epidemiology at the UCLA School of Public Health whose research focuses on US fertility patterns and other reproductive health topics, said in an email. “Untangling those factors is challenging.”
The US fertility rate has been trending down for decades
The US fertility rate has been trending down for decades
The 2025 rate was 9% lower than it was in 2019 before the Covid-19 pandemic and about 20% lower than it was 20 years ago.
Number of births per 1,000 women ages 15 to 44
A line chart showing a steep decline in the US fertility rate, from a high of 69.3 births per 1,000 women of reproductive age in 2007 down to 53.1 births per 1,000 women of reproductive age in 2025.
505254565860626466687053.1
Note: 2025 data on births is provisional and subject to change.
Source: US Centers for Disease Control and PreventionGraphic:Deidre McPhillips, CNN
The 2007 inflection point looks less significant when zooming out to a broader timeframe, some experts say. The general trend of declining fertility in the US started decades before the introduction of the iPhone. This is especially true when it comes to teen birth rates, which have been falling since the 1950s.
“Looking at that longer history gives us a better sense of the scope of explanations that make sense,” said Dr. Sarah Hayford, director of the Institute for Population Research and professor of sociology at The Ohio State University. “If you want to say this change has been happening for 100 years, it’s probably some factor that’s been continuous for 100 years and not something that happened 15 years ago.”
There’s also a very long history of linking changing technology to changing birth rates, Hayford said. Studies in the 1960s and 1970s looked at how the spread of radio and television may have been exposing people to ideals about small families.
New iPhone owners exit Apple's flagship store on Fifth Avenue, in New York, on June 29, 2007.
Michael Nagle/Getty Images
“The bigger picture view is that exposure to technology sort of changes your sources of information and ideas about what kinds of families are desirable and what kind of lives are desirable more generally,” she said. “The idea that you would see this very sharp effect in 2007 with a very specific technology, I’m a little more skeptical about.”
The timeframe that the new research focuses on also marks a period when access to IUDs and injectable contraception expanded markedly for young people in the US, Hayford said. For her, this draws a much more direct line to lower teen birth rates and fewer unintended pregnancies than smartphones.
The concept of a smartphone’s functions has also changed dramatically since it was introduced. The first iPhone let people browse the internet on the go and take pictures on their phone, but there were far fewer apps and no wide use of social media. Dating apps became popular in the mid-2010s, and OnlyFans launched in 2016.
“People often associate smartphones with addictive scrolling, highly personalized content, and digital substitutes for face-to-face interaction. The period studied here largely predates the widespread adoption of many of those features,” Gemmill said.
A difficult policy question
The researchers on the new study are clear that they don’t think smartphones are the only reason for the decline in the US fertility rate.
“We’re not saying this is the only factor. We’re saying it’s a major factor,” Myers said, and she says the study was designed to account for as many different confounding factors as possible. But it’s a difficult policy problem to solve, if the goal is to bring the fertility rate back up, she said.
“I think it’s policy-relevant because I’m worried that we’re not fully understanding why fertility is going down and that we’re looking in the wrong places,” Myers said. “But then, at the same time, I don’t know that I have a ready policy prescription for a phones story. Nobody thinks the government’s going to come take away all our phones, and I’m not suggesting that they should.”
A pronatalist movement has gained momentum under the Trump administration, buoyed by policy moves geared toward encouraging people to have more children.
“Maybe the answers revolve around how policymakers can foster human face-to-face interaction going forward rather than specific financial incentives,” Hooper said.
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