By Dr. Mercola

If you want to give your child a head start in life, do them a favor and keep the TV turned off as much as possible. And at the very least, make sure you do not put a TV in your young child’s bedroom.

It may seem harmless, and perhaps even educational, to let your child watch some TV, but as the latest research shows doing so may actually hinder their cognitive development.

TV Makes It Harder for Preschoolers to Understand ‘Theory of Mind’

Theory of mind is an important milestone in social and cognitive development, which children typically reach during their preschool years. A developed “theory of mind” allows children to understand differences between mental states like beliefs, desires, and pretend, while also understanding that others’ beliefs and desires may be different from their own.

A more developed theory of mind leads to better social relationships. Even at a young age, this developmental milestone allows for more cooperation and sensitivity among children, and less aggressive behaviors.

The research is quite clear that keeping children engaged via face-to-face conversations, imaginative play or reading is far better for their emotional and physical health and development than watching TV. It might even make them more tolerant of others’ beliefs as they get older.

Indeed, new study of children aged 3 to 9 years found that kids with TVs in their bedrooms, and those exposed to more background TV, performed more poorly on theory-of-mind assessments.¹ That is, they had a lower understanding of different mental states, including other people’s beliefs and desires.

Children May Have a Hard Time Deciphering ‘Feelings’ from TV Shows

It’s thought that children may have difficulty understanding what a person is thinking or feeling when watching them on TV. On the other hand, reading stories in books is beneficial because it often explains how a person is feeling and why. Having conversations in-person also help children to understand such distinctions.²

This might explain why the researchers found that children whose parents watched TV with them and explained what was happening scored better on the theory-of-mind assessment.

So if you are going to let your child watch TV, make it a point to have a conversation about it… but do be sure to limit your child’s ”screen time” regardless. The research is quite clear that more than two hours a day of screen time is associated with increased emotional and behavioral difficulties. According to one study:³

• Children who spent more than two hours a day watching TV or using a computer were 61 and 59 percent more likely to experience high levels of psychological difficulties, respectively
• Children who spent more than two hours a day watching TV, and also failed to meet physical activity guidelines, were 70 percent more likely to experience high levels of psychological difficulties

TV Is Linked to Childhood Obesity

Another reason to carefully limit, or altogether restrict, your child’s TV watching?  A number of studies have shown that the more time you spend watching TV, the more likely you are to develop metabolic syndrome, which is characterized by overweight, elevated insulin levels and hypertension (high blood pressure), type 2 diabetes, and obesity. This holds true both for children and adults, and it's nothing new.

More than 20 years ago, a study by researchers at Johns Hopkins University School of Medicine, along with experts at the US Centers for Disease Control and Prevention (CDC) and the National Institutes of Health, concluded that a child's weight increases with the number of hours he or she spends watching television each day.

Adults are similarly affected, by the way, with research showing that watching more than 14 hours of TV per week was associated with an increased risk of insulin resistance, obesity, and high cholesterol in both men and women.⁴

Earlier this year, research again showed that kids who used electronic devices at bedtime were nearly 1.5 times more likely to be overweight. Among those who had three or more such devices in their bedroom (such as a TV, computer, and video games), the risk jumped to over 2.5 times.⁵

Part of the problem is that the kids are staying up later than they should to watch TV or play video games, and this means they’re sacrificing valuable sleep time (and lack of sleep is linked to weight gain). TV also encourages obesity by increasing sedentary behaviors and exposing kids to significant amounts of junk-food marketing.

The longer you watch, the easier your brain slips into a receptive, passive mode, meaning that messages are streamed into your brain without any participation from you. (This is an advertiser's dream, and likely one of the reasons why TV advertising—particularly ads directed at children and teens—works so well.)

TV Watching May Numb Kids’ Brains: 15 Health Risks Revealed

Dr. Aric Sigman, a British psychologist, analyzed 35 different scientific studies on television and its effect on the viewer.⁶ He found the damage comes not from the TV programs themselves, but from the vast amount of time kids are spending watching television and computer screens.

This activity produces an almost narcotic effect on your brain, actually numbing areas that would be stimulated by other activities, like reading. Dr. Sigman has identified 15 negative effects that he believes can be blamed on watching television, stating:⁷

“Watching television, irrespective of the content, is increasingly associated with unfavorable biological and cognitive changes. These alterations occur at viewing levels far below the population norm. Given the population’s sheer exposure time to this environmental factor it is more than puzzling to consider how little awareness and action has resulted.”

The risks Dr. Sigman revealed include:

Obesity	Delayed healing	Heart trouble	Decreased metabolism	Damaged eyesight
Alzheimer's disease	Decreased attention span	Hormone disturbances	Cancer	Early puberty
Autism	Sleep difficulties	Increased appetite	Limited brain growth	Diabetes

How Much TV Is Too Much?

According to Dr. Sigman and other experts, children under age 3 should watch no TV at all, while those ages 3-7 should watch no more than 1.5 hours a day. For older kids, two hours of TV and/or computer/video game use should be the daily limit. You may choose to watch less than this, of course, but ideally not more. For comparison, the average child in the US watches more than 24 hours of TV a week…⁸

If you’re having trouble getting your kids to cut back, one of the best ways is to make sure there’s no TV in their bedrooms. One study showed that having a TV in the bedroom increased viewing time by nearly nine hours a week.⁹ Next, turn off the main TV in your home as much as possible; avoid using it for “background noise,” as this, too, is linked to negative effects in kids.

You can also shift your former TV time into family time. Spend time cooking a meal together, chatting or being active by riding bikes, going for hikes, swimming, ice skating, and engaging in other vigorous activities as a family. When your kids are older, they certainly won’t miss the hours they didn’t spend watching TV… but they will remember all the extra time you spent together as a family.