If you’re like many people, you may have decided that you want to spend less time staring at your phone. It’s a good idea: an increasing body of evidence suggests that the time we spend on our smartphones is interfering with our sleep, self-esteem, relationships, memory, attention spans, creativity, productivity and problem-solving and decision-making skills.
But there is another reason for us to rethink our relationships with our devices. By chronically raising levels of cortisol, the body’s main stress hormone, our phones may be threatening our health and shortening our lives.
Until now, most discussions of phones’ biochemical effects have focused on dopamine, a brain chemical that helps us form habits — and addictions. Like slot machines, smartphones and apps are explicitly