Mary Poppins they are not. A French study has found that 58 percent of under-twos have used a tablet or mobile phone, and while some parents boast of limiting their baby’s screen time, the American Academy of Pediatrics calls for complete prohibition. It’s too soon for researchers to gauge screen impact, but they’ve proven to overstimulate baby mice, making them more prone to hyperactivity and cocaine addiction. Some say moderate interactive app use can aid development; others warn passive viewing can impair it. Best bet? Pocket your own device and pay more attention.