Q: Why are so many of us addicted to our smart phones (with their emails, social media and games)? A: Smartphones are the perfect delivery devices for apps and platforms that are embedded with a range of hooks that are designed to capture our attention. Those apps draw from a menu of psychological techniques that are known to motivate and engage humans (and often other animals, too). For example, we’re driven to close open loops, including goals that are half-complete and half-told stories; we seek positive reinforcement, particularly when it’s not guaranteed and there’s a chance, however slim, of hitting...