The American Academy of Pediatrics (AAP) recommends that children under two years of age watch no TV and that those older than two years watch no more than one to two hours of quality programming per day. During a child's first two years, brain development is very critical, and TV could hinder this development by taking the place of playing, exploring, and interacting, activities that lead to learning and healthy social and physical development. Educational TV, used in moderation, can be beneficial to children over two years old by reinforcing things they have already learned and introducing them to new information.
No matter what the programming, parents need to be mindful that TV can take the place of physical activities, homework, reading, playing, and family time and is associated with weight gain in children. So, the bottom line is: Choose the TV your children over two view wisely, and limit the time they watch.