“Unfortunately, distraction is contagious. When smokers get together, the first one to take out a pack sends a cue, and when others notice, they do the same. In a similar way, digital devices can prompt others’ behaviors. When one person takes out a phone at dinner, it acts as an external trigger. Soon, others are lost in their screens, at the expense of the conversation. Psychologists call this phenomenon “social contagion,” and researchers have found that it influences our behaviors, from drug use to overeating.”