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A Fresh Start?

The impact of high school start times on non-cognitive factors
Line of alarm clocks telling different times

At a time when the health and wellbeing of students is critical, schools are having to assess and adjust their school days — creating an opportunity to reevaluate the role that scheduling and start times play in overall student success. While health professionals and education researchers have linked school start times and adolescent sleep patterns with overall health and, in some cases, academic performance, a recent study by Ph.D. student Matthew Lenard and two colleagues from North Carolina State University, professor Melinda Morrill and graduate researcher John Westall, found evidence that school start times also impact noncognitive factors like attendance and dropout rates.

Lenard and his co-authors looked at the effects of a significant policy change that occurred in 2014, when five comprehensive high schools shifted their start times 40 minutes earlier to align with early-start high schools across the district. The move by the school district — taking start times from 8:05 a.m. to 7:25 a.m. — contradicted other recommendations, including the start time recommended by the American Academy of Pediatrics (AAP), which is 8:30 a.m.

To study the impact of the start time changes, the researchers looked at annual data for students affected at some point in high school and compared them to students from earlier cohorts that were not affected and students at other high schools within the district. 

They looked not only at cognitive impacts (measures like test scores) but outcomes related to student engagement. Their findings confirmed prior work and suggested that the impacts may be even more important than previously documented. 

Major Findings

  • Lenard and his colleagues did not find statistically significant effects of the early start times on students’ ACT scores, suggesting that the true benefit to later start times might not be captured by test scores alone. However, the researchers could not rule out the possibility that start times influence test scores. Lenard explains that “the ACT isn’t a state accountability test. It captures cumulative knowledge so it may not be as sensitive to differences in high school environments.”
  • The early start time significantly affected other measures of student success and engagement. Schools that started latest had, on average, lower absenteeism and tardiness rates. However, when shifting start times 40 minutes earlier, those benefits disappeared. Dropout rates were also slightly higher under an early start time.

The two findings, taken together, show that policy consequences can vary across domains. “The message in our results is that not everything we learn about the effects of policies can be captured by test scores,” Lenard says. “We quantify this, and we’re among the first to do so in the context of an actual start time policy.”

Other Findings

  • Duration matters: Students who were exposed to an early start time for all four years of high school had a larger negative result, on average.
  • Gender matters: Male students had stronger negative results, on average.  
  • No significant impact on students who were already high achieving: The study failed to find negative effects of early start times on students who were already performing in the top third of middle school achievement.


The researchers’ results suggest that leaders need to be sure they are considering metrics beyond test scores to ensure the school is taking care of children first. This is even more critical in a pandemic when a child’s health is on the line. Policy changes, such as starting school earlier, can have broad impacts on students’ lives.

“I think we have to figure out a way to look at relationships across school schedules, learning time, and other outcomes,” says Lenard. “We’re always concerned with accountability as linked to test scores, but there are many other outcomes that help us understand how a child learns and those include things like health, perseverance, and executive function.”

Key Takeaways

  • Student achievement is only one indicator of success. Metrics like absenteeism and tardiness can provide a different and more well-rounded picture when evaluating the success of a program or policy change.
  • There is an opportunity to use the flexibility provided by remote learning to reimagine the scheduling and logistical factors to promote the overall health and welfare of children.

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