Happiness is declining among America's young adults, and no one seems to agree on why.

In this year's World Happiness Report, which ranks 143 countries across measures of life satisfaction, the U.S. fell eight spots from No. 15 to No. 23 on the list. It's the first time the U.S. has not been considered one of the top-20 happiest countries in the report's 20-year history.

Researchers identified a troubling culprit for America's precipitous fall: young people. While Americans older than age 60 ranked No. 10 for happiness, those younger than 30 ranked 62nd  — a stark generational split.

The finding comes amid growing evidence that, as a group, young people's outlook and mental health have eroded in recent years, with devastating consequences.

Rates of teen anxiety and depression "rose by more than 50% in many studies from 2010 to 2019," according to Jonathan Haidt, an NYU social psychologist and author of recent bestseller "The Anxious Generation." The book focuses on those born after 1995. Meanwhile, suicide rates of Americans ages 10 to 24 increased 62% from 2007 to 2021, especially among young girls, the CDC reports.

The problem is clear, but the root cause is not.

Haidt and other researchers argue that technology and social media have led to an epidemic of isolation and loneliness. However, a growing body of research reveals more nuanced reasons for the decline, including economic and systemic failures, institutional distrust and young people's increasing dread that they will be worse off than their parents and grandparents.

Social media can 'set developing brains into a habitual state of defensiveness'

In his 2023 report "Our Epidemic of Loneliness and Isolation," U.S. Surgeon General Vivek Murthy named social media as one of the main reasons young people feel more alone.

"Several examples of harms include technology that displaces in-person engagement, monopolizes our attention, reduces the quality of our interactions, and even diminishes our self-esteem," Murthy wrote. "This can lead to greater loneliness, fear of missing out, conflict, and reduced social connection."

Haidt believes social media can hurt the developing brain.

"Kids going through puberty online are likely to experience far more social comparison, self-consciousness, public shaming, and chronic anxiety than adolescents in previous generations, which could potentially set developing brains into a habitual state of defensiveness," Haidt wrote for The Atlantic.

Zach Rausch, Haidt's lead researcher and an associate research scientist at NYU's Stern School of Business, says conversations on Instagram or text often don't cross over from digital to the physical world.

"We used flip phones to connect with each other in order to eventually meet in person," Rausch says. "The online world is kind of the opposite. We connect in order to stay there. And our argument is that that's not sufficient."

"The Anxious Generation" doesn't claim that eliminating social media is a panacea for loneliness and depression, Rausch adds.

"Of course it's the case that there are many factors that drive adolescent mental health problems, and social media is not the only thing that causes problems," he says. "And I hope that that's really clear in the book." 

Rather, it aims to examine what shifted in our culture at a very specific time in recent history. For Haidt, it's clear that what changed is technology.

"When we look at what has happened to young people, especially adolescents, and especially adolescent girls, what we find is that rates of poor mental health, anxiety, depression, self-harm — not just in the U.S., but in many countries around the world — are generally stable up until around 2010," Rausch says. "And then there's this uptick. So what our book is trying to do is find out what happened during this period."

'The association between social media and loneliness is non-existent'

The link between social media use and unhappiness or loneliness might be more tenuous than previously thought, says Jeffrey Hall, a communications professor at the University of Kansas who studies relationships and social interaction.

"The association between social media and loneliness is nonexistent in several different meta-analyses," Hall says.

His findings point to a confluence of systemic failures specific to the United States: "Money, lack of being able to settle down, institutional distrust — those are major factors making people feel like they can't be positive about the future," he says. 

Candice L. Odgers, a professor in the psychological science department at the University of California, Irvine, says Haidt's findings are unsupported by research.

"Hundreds of researchers, myself included, have searched for the kind of large effects suggested by Haidt," Odgers wrote in the academic journal Nature. "Our efforts have produced a mix of no, small and mixed associations. Most data are correlative. When associations over time are found, they suggest not that social-media use predicts or causes depression, but that young people who already have mental health problems use such platforms more often or in different ways from their healthy peers." 

To Hall, the effects of platforms like Instagram and TikTok are, at the very least, overstated and ignore how varied social media usage can be. "Social media is not this monolithic experience where everybody experiences the same thing," he says.

That's not to say that platforms like Instagram are helpful or healthy for everyone.

"I think for people in really desperate need of connection, social media is probably an incomplete solution at best," Hall says.

Another change that could have affected recorded rates of mental illness in young people: the Affordable Care Act, which was enacted in 2010 and provided health insurance coverage and mental health services to more Americans. With increased coverage came an increase in care and diagnoses, possibly uncovering more cases.

Mark Zuckerberg, CEO of Facebook and Instagram owner Meta, has said "mental health is a complex issue" and that existing research does not show a "causal link between using social media and young people having worse mental health outcomes."

Still, he said he takes the issue seriously and the company has added guardrails, such as hiding content and search results about sensitive issues, like self-harm, from teens and instead providing resources. TikTok implemented similar search filters, according to the company.

Social media 'magnifies this steep inequality'

A slew of economists and social scientists maintain that the thesis of Haidt's book and the tendency to blame social media ignores some of the larger, chronic pressures that harm young people's mental health.

Constant virtual connection with millions of people can bring into sharper focus the moat that exists between the haves and have-nots, says Jennifer Breheny Wallace, author of "Never Enough: When Achievement Culture Becomes Toxic — and What We Can Do About It."

"I don't believe social media is the root of the struggles we are seeing, but it is exacerbating the social comparison that is rampant in our society," she says. "It magnifies this steep inequality we've seen in our country."

Some 44% of U.S. teens ages 13 to 17 say it's harder to be a teenager today than it was 20 years ago, according to Pew Research. The No. 1 reason they provided was "more pressures and expectations" (31%), followed by "social media" (25%) and "the world/country has changed in a bad way" (15%).

Many of the pathways to wealth that were available for baby boomers or even Gen X are much narrower for Gen Z, says Kyle K. Moore, an economist at the Economic Policy Institute. 

"We live in a country where wealth is really important to securing economic well-being," he says. "There aren't a lot of vehicles to build wealth." 

Homeownership, for example, has become increasingly out of reach since the 1980s.

'I Zillowed our house and I can't afford it'

In her book, Wallace interviewed adolescents about how they view their economic futures. 

She found that even 14-year-olds are stressed about the housing market: "One student I interviewed said to his mother in 8th grade, 'If I wanted to be an architect, where would I live?' She said, 'You can live anywhere.' He said, 'I Zillowed our house and I can't afford it.'" 

The sentiment extends to retirement and overall financial happiness, Moore says. "If you talk to Gen Z about whether they are going to retire, a lot of them might laugh at you." 

Even if their parents or grandparents were able to retire at 65, many young people are witnessing the elderly in their lives struggle to exist comfortably. 

"I think Gen Z and millennials have the lived experience of seeing parents and grandparents not having what they thought they would have and continue to work longer than they anticipated working," Moore says. 

Believing they have even fewer avenues to financial security than their parents can be disheartening, he adds.

Yet Rausch says the research doesn't bear out economic issues at the core.

"If the economy was the main factor driving the [mental health] crisis, then we would expect that as the economy changes the crisis would generally get better, and that's not what we found," Rausch says. "Unemployment levels started to rise after the [2008 financial] crisis, and then they started to fall down as adolescent depression and self-harm continued to spike." 

'There's a sense that the future is looking pretty bleak'

Gen Z's perception of their own financial stability can also affect their relationships, which strongly contribute to overall life satisfaction, Hall says.

Positive relationships of all kinds are one of the most important pillars of happiness, according to an 85-year-long Harvard University study. 

In 1990, 29% of Americans between ages 25 and 54 lived alone and were unpartnered, according to data from Pew Research Center. In 2019, that number was 38%. And more recent data shows that married people tend to be significantly happier than unmarried people, according to a 2023 report from the University of Chicago. 

"A lot of young people are not getting married and settling down and having kids because they can't afford it," Hall says. 

Having kids is not a shortcut to happiness, but the reasons young people are less interested in child-rearing than previous generations might reveal deeper truths about how they view the future.

Of adults ages 18 to 49 who don't have kids and say they are unlikely to, 38% say a major reason is because they are concerned about the state of the world and 26% cite concerns about the environment, according to data from Pew Research Center.

Dr. Orna Guralnik, a New York City-based clinical psychologist and host of the show "Couples Therapy," says she is increasingly seeing couples opt out of having children because of their lack of faith in world leaders. 

"There's a sense that the future is looking pretty bleak, and there's no sense that the people in charge — the leaders, the government, the policies — are doing anything about it," Guralnik says. 

Meanwhile, Rausch is skeptical that large-scale stressors like climate change are driving recent youth unhappiness, saying there are "no clear reasons why climate change in and of itself would be impacting kids" differently from how it impacts other age groups.

Navigating an uncertain future

Haidt proposes a few solutions for Gen Z and their parents to curb social media and smartphone reliance. Some, like silencing notifications, can be easily implemented. Others, like making schools phone-free, are more difficult but have already started to take hold in some of the country's largest school districts.

In June, the chancellor of New York City Public Schools said the district plans to ban smartphones in schools. It followed an announcement by the Los Angeles Unified School District that it will ban student cellphone and social media use starting next year. 

While limiting social media use could result in more and better in-person connections, it does not address the cultural or economic realities today's young people are facing.

Researchers increasingly agree that curbing screen time is not a panacea for unhappiness and kids are not made more lonely because of Instagram or TikTok.

"Lonely kids turning to social media to cope — that is a very different narrative from social media is making them lonely and ruining their lives," Hall says.

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