Recruiting headteachers as inspectors assumes good people make good inspections. Fifty years of social psychology suggests it’s not that simple. In 1971, American psychologist Philip Zimbardo took two dozen psychologically healthy young men, flipped a coin, and made half of them prisoners and half of them guards in a mock jail beneath Stanford’s psychology department. The study was meant to run for two weeks. It was abandoned after six days, when the “guards” – ordinary students, selected for their normality – had become authoritarian and, in some cases, cruel. Become a member for unlimited access to Schools Week subscribe Our members enjoy early access to exclusive content and in-depth articles before anyone else. Get expert journalism, experience fewer ads, and unlock a growing range of member benefits.