Spanking is a less popular form of discipline today than it was 20 years ago — in no small part because so many parenting experts have spoken out against it. Still, many caregivers in the United States argue that it’s “sometimes necessary” to teach kids how to behave. Recently, the American Academy of Pediatrics (AAP), an organization of 67,000 physicians, took a strong stance against corporal punishment as a disciplinary tool.

Spanking not only ineffective, the AAP says, but there is evidence that it can increase aggression in children over time and cause damage to a growing brain. Its policy statement1 advises against the use of any form of physical discipline or verbal abuse intended to shame and humiliate a child. The basis for this advice is recent research and a new understanding of brain development, which show the following: Any positive behavioural effect of spanking is…