Many parents like to give their two or three-year olds a video tablet to keep them busy, thinking the educational apps are good for them. But that may not be good for them in the long run. A new study published in the journal JAMA Pediatrics shows among toddlers, spending a lot of time staring at screens is linked with poorer performance on developmental screening tests later in childhood.

            Dr. Stephen Lauer is a pediatrician at The University of Kansas Health System, and he’s not surprised by the study. In the video, he says that parents can think of screens like they do giving junk food to their kids: In small doses, it’s OK, but in excess, it has consequences. He says the American Academy of Pediatrics recommends limits on screen use for preschool children ages 2 to 5 to just one hour a day of high-quality programming. He says the study shows higher screen time viewing at 2 and 3 years of age was associated with children’s delays in meeting developmental milestones at 3 and 5 years of age. He says that’s because a toddler’s brain is at a critical time of development, and the two-dimensional aspect of screens can reinforce a false sense of reality. Lauer says children of that age are much better off when someone reads to them, and interacts with them about the story, which helps establish a three-dimensional reality. Lauer also says excessive screen time can lead to a decrease in sleep in children, which can also cause poorer development.