A study was done on Japanese children. In this study, children from the ages of five all the way to eighteen who watched between zero hours and four hours of television a day were the subjects. The average child watched around two hours of television per day, but those who watched closer to four hours a day tended to have a higher gray matter volume “in regions toward the front and side of the head.”

            However, this association between more television watched, and more brain volume is probably not a good thing, as higher brain volume in the subjects was correlated with a lower verbal IQ. While this study is only one of the first to analyze television viewing through the lens of developmental science, and there’s not a lot of other studies that can back this one up, it’s fair to say that the two variables–television hours watched and lower test scores–are correlated. This is not to say, of course, that a person who watches a lot of TV couldn’t be a genius, as much as it is also not saying that watching no TV will make you a better test taker. There could be, and probably are, many other factors weighing in on this study.

            I watch a lot of TV. I have always watched a lot of TV. I’m not trying to hide that. But I wouldn’t consider myself less smart than the vast majority of my peers, and I definitely wouldn’t do that because of how much TV I watch. There are all kinds of intelligences one can have, so even if you might score lower on a verbal IQ test, you could easily be fantastic at another subject. The scores and the hours watched are correlated, but the study doesn’t say anything about other subjects.