Researchers believe that the students, especially younger ones, may have turned to more disruptive behavior when they no longer had access to their phones.

Yeah, no shit? Phones tend to serve as a distraction that kills boredom; disruptive behavior is frequently (maybe usually) the result of boredom.

“One conjecture is that this resembles, to some degree, withdrawal symptoms,” he said. “Students are unhappy and disruptive the moment their phones are taken away.”

They’re understandably bored and then, understandably, try to kill their boredom in other, more disruptive ways. I for one very much prefer students being on their phones (or other devices) to beating each other up, damaging property, or psychologically insulting each other out of boredom! No idea what about this is supposed to resemble withdrawal symptoms.