How massive online experiments (MOEs) can illuminate critical and sensitive periods in development

The fact that children are far more likely to successfully acquire a variety of new skills and knowledge than are adults is so clearly evidenced in everyday life that it hardly needs scientific confirmation. However, despite four decades of intensive research, the reason why remains controversial. In fact, the terms of the debate about critical periods in language have hardly changed since the 1960s. I argue that this is because the standard...