Have you ever felt your melting brain dribble out of your ears after watching a few hours of TV? Didn’t think so. If you said yes, definitely get off your computer and go see a doctor. For the rest of you without liquified brains. I’m sure you’ve heard about some of the negative aspects of watching TV. I know, the Big Bang Theory is super funny but you should really go outside. Humans are not meant to spend most of their time sedentary, that means you! It has long been known that the advent of television has contributed to obesity related diseases. But does it make you dumb? There is some evidence out there that suggests just that! Before you call your mom and tell her that your bad mid term grade was Modern Family’s fault, lets check it out.
A study done by researchers at the University of Cambridge looking into this question was published in the International Journal of Behavioral Nutrition and Physical Activity. They started with 845 adolescents between the ages and 14-15 and monitored their screen time, physical activity and study time leading up to when they took the GCSE, a pseudo-equivalent to a high school diploma in the United Kingdom. They adjusted for BMI z-score, deprivation, sex, season and school before analyzing the results. After they got the exam scores back and analyzed the results they uncovered some fairly predictable trends. Those who spent an extra hour everyday watching TV or playing video game scored an average 9.3 less points. For a test that is only out of 58 points, that is the difference between and A and B. The kids who spent an extra hour every day studying scored a whopping 23.1 more points on average and the kids who spent an extra hour exercising scored an average 6.9 more points more.
Based on these results, it is clear that studying makes you do better in school (duh). We’re interested in the difference in scores between screen time and physical activity. These results do suggest that screen time is a significant factor in worse test scores. However, I don’t feel that this study did a great job controlling for confounding variables. Kids between 14 and 15 in the UK have never taken the GSCE before and based on the researchers’ methods they are getting these variances by comparing test scores across the 845 subjects. It is possible that IQ is the main determinant of GSCE score and that more or less physical activity/screen time is a non factor. It is also a possibility that if one of the subjects is inherently smarter he/she will be more inclined to spend less time playing video games and prefer to spend their time reading or playing outside. This was an observational study because the independent variables, physical activity and so, were not manipulated by the researchers in any way. Therefore, their results can only suggest a correlation at best but have means of establishing a causal relationship.
This doesn’t mean that I’m suggesting that watching copious amounts of TV is okay! In fact I urge you to do the exact opposite. Children in this country spend an average of 1,620 minutes a week watching television. That’s an incredible 27 hours or 16% percent of the hours in a week. If we assume that a child gets around 9 hours of sleep per night, that means they spend 25.7% of their waking hours watching TV. Even if the Cambridge study is only correlational, there is a definite possibility that screen time inhibits learning. For the rational person, unless you value hours spent watching TV more than higher grades in school, it is safe to say that spending more time not watching TV is worth it. Maybe it’ll keep your brain from melting too.