This never-ending stream of interruptions—this constant fragmentation of attention—takes a toll on adolescents’ ability to think and may leave permanent marks in their rapidly reconfiguring brains. Many studies find that students with access to their phones use them in class and pay far less attention to their teachers.[46] People can’t really multitask; all we can do is shift attention back and forth between tasks while wasting a lot of it on each shift.[47] But even when students don’t check their phones, the mere presence of a phone damages their ability to think.
