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October 15, 2019

California became the first US state to mandate later start times for middle and high school students

California became the first US state to mandate later start times for middle and high school students

California Governor Gavin Newsom signed legislation on Sunday that will require most middle and high schools in the state to start later in the morning, bringing them in line with research that shows teenagers benefit academically and in other ways.

Middle schools will not start earlier than 8:00 am and high schools no earlier than 8:30 am, with some rural schools being exempt from the new law. The change will be phased in over a period of three years for contractual reasons.

“The science shows that teenage students who start their day later increase their academic performance, attendance, and overall health,” said Newsom.

Teny Maghakian Shapiro writes about the educational effects of school start times for IZA World of Labor. She notes how in the early 1990s, researchers discovered that adolescents experience major changes in their circadian rhythm—a hard-wired “clock” in the brain that controls the production of the sleep-inducing hormone melatonin—with an approximately three-hour shift toward later bed and wake-up times, making 7:30 am for an adolescent equivalent to 4:30 am for an adult. 

“Ideally, students whose school starts early would go to bed early to ensure a full night’s sleep,” she writes. “However, because of this delay in circadian rhythm, adolescents are unable to fall asleep early enough to get eight or nine hours of sleep before they need to wake up for school, leading to an increase in daytime sleepiness.” 

Research indicates that lack of sleep increases the risk of depression, anxiety, suicidal thoughts, and motor vehicle accidents among teens. Whereas those who get enough sleep are less likely to be late and absent from school, and more likely to be alert and get better grades.

Critics have opposed delaying school start times for a number of reasons, including the impact on parents’ work schedules and the consequences for after-school activities.

Shapiro writes that studies have found sizable gains in test scores and grades from later start times, with a one-hour delay having the same effect as being in a class with a third fewer students or with a teacher whose performance is one standard deviation higher. Later start times are also shown to improve non-academic outcomes, such as mood and attendance, and reduce the frequency of automobile accidents. 

She says that “[w]hile changing start times is not costless, the benefits are likely to outweigh the costs.”