Having Your Smartphone Nearby Takes a Toll on Your Thinking (Even When It’s Silent and Facedown)

people performed worst when their phones were nearby, and best when they were away in a separate room ... merely having their smartphones out on the desk led ... impairment of individuals’ cognitive capacity — on par with effects of lacking sleep... our smartphones can adversely affect our ability to think and problem-solve ... even when they are powered off altogether...
the mere presence of our smartphones is like the sound of our names — they are constantly calling to us, exerting a gravitational pull ... resist this pull ... impairing our cognitive abilities... how do we resolve this tension between the costs and benefits of our smartphones?