Library of CongressIn this 1905 photograph from the Library of Congress collection, a teacher holds a switch as a student is punished by wearing a dunce cap.
A documentary from APM Reports explores how a get-tough attitude prevailed among educators in the 1980s and 1990s. But research shows that zero-tolerance policies don't make schools safer and lead to disproportionate discipline for students of color.
Part of the documentary focuses on discipline in Denver Public Schools -- Colorado Matters spoke with DPS Superintendent Tom Boasberg earlier this week and asked him about the issue.