Parents are often shocked when I tell them that pediatricians think it’s a bad idea for children to watch TV before age 2. Surveys tell us about 40% of infants are watching some sort of video by age 5 months, and by age 2 the number rises to 90%.
Early brain development
To answer these questions we have to return briefly to the child’s developing brain. Kids’ brains grow profoundly during the first 3 years of life, with the brain tripling in mass in just the first 12 months. The stimuli children experience during this period profoundly influence brain development. Images on screens behave in ways that differ dramatically from those in the real world. Because we’re all steeped in the visual language of screens, it’s easy to forget those differences until we think about them.
Imagine a ball in real life and a ball on TV. Infants are developing 3-dimensional vision. The world of the screen exists in 2 dimensions, so the ball is just a flat, shaded circle. If you roll a ball across the floor it proceeds in a single motion, slowing gradually until it stops. The same action on TV is broken up—you see the ball leave someone’s hand, then there’s a shot of it in motion, then a picture of the ball at rest. If your infant wants to grab a ball in real life he’ll lunge for it, grasp at it, or crawl after it. The stuff on the screen just disappears, to be replaced by other stuff; you can never get your hands (or mouth) on it. Infants may stare at the bright colors and motion on a screen, but their brains are incapable of making sense or meaning out of all those bizarre pictures. It takes 2 full years for a baby’s brain to develop to the point where the symbols on a screen come to represent their equivalents in the real world.
Because of this confusion, children up to age 3 learn better from the real world than they do from any screen, especially when it comes to language. They do seem to learn a little more if they’re watching in the company of a person who is talking to them about what they’re seeing, in the same way you would while looking at a picture book.
Where's the harm?
So sure, babies and toddlers don’t get anything out of watching TV, but if they seem to like it, where’s the harm? If a little TV is what it takes for you to get dinner on the table, isn’t it better for them than, say, starving? Yes, watching TV is better than starving, but it’s worse than not watching TV. Good evidence suggests that screen viewing before age 2 has lasting negative effects on children’s language development, reading skills, and shortterm memory. It also contributes to problems with sleep and attention. If “you are what you eat,” then the brain is what it experiences, and video entertainment is like mental junk food for babies and toddlers.
The problem lies not only with what toddlers are doing while they’re watching TV; it’s what they aren’t doing. Specifically, children are programmed to learn from interacting with other people. The dance of facial expressions, tone of voice, and body language between a toddler and parent is not only beautiful, it’s so complex that researchers have to record these interactions on video and slow them down just to see everything that’s going on. Whenever one party in this dance, child or parent, is watching TV, the exchange comes to a halt. A toddler learns a lot more from banging pans on the floor while you cook dinner than he does from watching a screen for the same amount of time, because every now and then the 2 of you look at each other.
Just having the TV on in the background, even if “no one is watching it,” is enough to delay language development. Normally a parent speaks about 940 words per hour when a toddler is around. With the television on, that number falls by 770! Fewer words means less learning. Toddlers are also learning to pay attention for prolonged periods.
Toddlers who watch more TV are more likely to have problems paying attention at age 7. Video programming is constantly changing, constantly interesting, and almost never forces a child to deal with anything more tedious than an infomercial.
After age 2 things change, at least somewhat. During the preschool years some children do learn some skills from educational TV. Well-designed shows can teach kids literacy, math, science, problem-solving, and prosocial behavior. Children get more out of interactive programs like Dora the Explorer and Sesame Street when they answer the characters’ questions. Educational TV makes the biggest difference for children whose homes are the least intellectually stimulating.
What you can do
Naturally, children learn more when they watch TV with a parent than if they watch alone. Content matters, a lot. All programs educate kids about something, but stick with ones that are designed to teach children stuff they should actually know.
Regardless of content, cap your child’s TV time at 2 hours a day. Remember, too, TV is still TV whether you actually watch it on a TV screen or on a mobile phone or computer.