It's practically a ritual: As soon as we sit down on the bus or get in line at the post office, we pull out our phones. Studies show average Americans check their phones almost 100 times a day, spending more than five hours daily staring at that pocket-sized screen. While scrolling through social media or checking sports scores may seem like a good way to kill time it may come at a social cost, according to a new study by Sandy Campbell, Ph.D. 24.