After interviewing several people about their relationship with email, Mark has noticed that, for some people, email is an extension of autonomy—it’s about having control. One subject, she said, told her, “I let the sound of the bell and the popups rule my life.” Compulsively checking email or compulsively clearing out queues of unread emails, then, can be a form of regaining some of that control. “So I might refine your theory to say that those who feel compelled to check email may be more susceptible to feeling a loss of control [and] in missing out on information,” Mark said.

When someone drops everything just to get an unread count back to zero, productivity might be taking a hit. “It takes people on average about 25 minutes to reorient back to a task when they get interrupted,” she says. Yes, that includes even brief interruptions, like dashing off a quick response to an email, and it often takes so long to get back on task because the project you start doing after handling an email often isn’t the same as the one you were already doing. (These interruptions are so integral to modern workflows, Mark says, that when people lack external interruptions, such as a coworker striking up a conversation, they voluntarily interrupt themselves—sometimes by checking email.)