Economist David Blanchflower studies happiness. And for more than two decades, the Bruce V. Rauner 1978 Professor has published over 30 papers revealing a stable pattern for how most people experience happiness and well-being over the course of a lifetime.

That pattern—replicated hundreds of times by other researchers—famously can be graphed on a U-shaped curve.

“Basically we found that people were at their unhappiest in middle age. You’re happy when you’re young, and you’re happy when you’re old—that’s the U shape,” says Blanchflower, a specialist in labor economics who served as a member of the Monetary Policy Committee of the Bank of England from 2006 to 2009. 

But recently, Blanchflower and his colleagues are seeing a worrying trend. The left arm of the U, —representing the young—is no longer pointing up. The reason? Around the world, young people have been reporting increasing unhappiness. And Blanchflower believes the advent of smartphones and social media may be largely to blame.

Though it was only noticed recently, the shift in the happiness trend began more than a decade ago, says Blanchflower. 

“The U-shaped curve was one of the most important patterns in social science, until it wasn’t,” he says. “What we’ve discovered is that, from around 2013, the U-shaped pattern suddenly starts to disappear. It’s not that the pattern we saw was wrong; it changed. We’re faced with a situation globally where there’s been a collapse in the well-being of young people, and especially young women.” 

Why suspect smartphones and social media? Since the first iPhone was released in 2007, the use of such technology has become ubiquitous, changing the way people, especially children, engage in social behavior.

“When kids spend time on smartphones, they don’t engage with people face to face, and they don’t do some of the things we adults did when we were kids,” Blanchflower says. “Neuroscientists say that when people interact with each other, their brains establish important pathways for social and emotional behavior.” 

He argues that the time children spend on smartphones is time that they otherwise would have spent engaging with others and developing their brains. Among other evidence, a recent report from the Centers for Disease Control and Prevention found that the more high school students use social media, the more at risk they are for being the victims of bullying and cyberbullying.

And Blanchflower himself recently published a paper in the International Journal of Wellbeing on how the experience of childhood traumas, including bullying, can have lifelong negative effects.

“Bullying has huge effects, even 50 years later,” Blanchflower says. “So cyberbullying is potentially going to have all kinds of harmful effects. It impacts your education, whether you have good relationships with people, how much you earn.”

Still, when they first noticed the change in the U-shaped graph, Blanchflower and his colleagues thought the trend might be related to major events, such as the COVID-19 pandemic or the financial crisis of 2008. But their deep dive into micro-data from major surveys in the U.S., Europe, and the U.K., among others, recently published in the journal PLOS ONE, showed that these events had only a short-term negative impact on reported well-being. 

In fact, these short-term crises created noise that masked the longer trend in the data, says Blanchflower. 

“We all thought, yes, COVID’s bad. But what we didn’t realize was that COVID was just extending the trend that had already been there. Now we’re trying to catch up because we got sidetracked by COVID and missed this long trend.”

The decline in youth happiness and well-being has been observed in many countries, including the U.K., the U.S., Canada, Australia, New Zealand, Scandinavia, the Netherlands, France, Germany, and Italy. Blanchflower has spent the past year working closely with the United Nations, studying international mental health trends. 

He is currently collaborating on several UN-commissioned working papers that look at well-being trends among the young around the world, and has already completed papers on the U.S., the U.K., Europe, Africa, and Latin America. Well-being has declined especially among young people connected to the internet, he says. (The papers are available on Blanchflower’s website.)

Some K-12 schools are already limiting students’ access to smartphones, and recently Australia banned access to social media platforms for children under the age of 16.

Blanchflower says understanding the cause of the trend is critical to finding ways to turn it around. “We don’t want a lost generation,” he says. 

He is working to organize a major conference in October with the United Nations Development Programme’s Human Development Report Office that will bring together experts, international policymakers, and leaders in higher education to share research and best practices for addressing the crisis.

The symposium will be hosted at Dartmouth, where President Sian Leah Beilock has made mental health a major priority.

“There’s growing consensus that this is going on,” he says. “There’s a debate about what’s caused it, how widely it’s spread, and what to do about it, and that’s what the experts are going to come together and debate. And we’re going to look at best practices around the world.”

Among other efforts to address mental health and well-being on campus, Dartmouth has unveiled Commitment to Care, which President Beilock has described as a comprehensive plan to strategically address undergraduate mental health, and appointed physician Estevan Garcia as the institution’s first chief health and wellness officer.