California Students Sleep More, Score Higher on Tests

California took a bold bet on science in 2019, and it's paying off for students across the state.

When Governor Gavin Newsom signed legislation requiring middle schools to start no earlier than 8 a.m. and high schools no earlier than 8:30 a.m., it sparked fierce debate. Parents worried about work schedules and morning carpools. School administrators protested the logistical nightmare. Many called it government overreach.

But the American Academy of Pediatrics, the American Medical Association, and the CDC all agreed on one thing: teenagers weren't getting enough sleep, and it was hurting them. California became the first state in the nation to mandate later start times, and the law took effect in the 2022-23 school year.

Now, three years later, researchers have the data. And the results are exactly what sleep scientists predicted.

Four academic researchers analyzed student data from 2022 to 2025 and published their findings through the National Bureau of Economic Research in May. Students are getting more sleep. They're experiencing fewer mental health problems. And most importantly, their test scores in both math and English have improved.

The gains showed up across all student groups, but they were especially strong among boys and Latino students. These are meaningful wins for California, a state that has struggled with academic achievement compared to other states.

"Rest and sleep are incredibly important in the function of schools," said Osea Giuntella, one of the study's authors.

The debate wasn't always this clear cut. In 2018, then-Governor Jerry Brown vetoed an earlier version of the bill, calling it a "one-size-fits-all approach" better left to local communities. Education leaders like Orange County's former superintendent Al Mijares argued the mandate would burden working families, especially those already facing economic challenges.

The Bright Side

Sometimes doing the right thing for kids means adults have to adjust. California families and school districts adapted to new morning routines, shifted extracurricular schedules, and figured out new carpool arrangements. The temporary inconvenience translated into lasting gains for student health and learning.

The research now settles years of debate with hard evidence. When policymakers listened to medical experts instead of logistical concerns, students thrived. California took a chance on putting student wellbeing first, and the science proved it was worth it.

Other states are now watching closely, considering whether to follow California's lead and give their own students the gift of sleep.