for students Later start time for teens improves grades, mood, and safety 8 Kappan December 2016/January 2017 KYLA L. WAHLSTROM (wahls001@umn.edu) is a senior research fellow and lecturer in the College of Education and Human Development at the University of Minnesota, Minneapolis. Pixland Fixing school time New research shows that high school students benefit in many ways from later start times. By Kyla L. Wahlstrom It all began with a phone call 20 years ago to the Center for Applied Research and Educational Improvement (CAREI) at the University of Minnesota in August 1996. The superintendent of Minnesota’s Edina School District was reaching out to CAREI, seeking to discover if the new change in the start time of their high school — from 7:20 a.m. to 8:30 a.m. — would have any effect. I took that call. When I learned the reason for the change — namely, that the district’s later start time purported to address developmental changes in the teenage brain related to sleep — I was skeptical. As a former teacher, school principal, and district office administrator in special education, I thought I had heard it all when it came to explaining teenage behavior. This association between brain devel- opment and teenagers was new to me.