This checking habit was inflamed by the phenomenon of “intermittent reinforcement.” Usually my email isn’t very rewarding, but occasionally—and I never know when—I get an email that’s great. This kind of unpredictable, variable, instantaneous reinforcement is the hallmark of many powerfully habit-forming actions, such as playing slot machines. Checking is also rewarding because it offers the possibility of resolution, which people crave—I get replies to my emails, I learn the definition for “claustral,” I see that 150 people commented on my post. And that feels good.
