That's true, but are TVs and comics in your pocket or beside your bed 24/7 like phones? Are they computers that also directly attach you to several friends, family, acquaintances, and strangers instantaneously across several avenues? Do they notify you that you are "missing" something? I don't think there's any example in human history of things that have garnered the daily and sustained use of human attention more than smartphones, tablets, and the Internet.

There is the book The Shallows: What the Internet Is Doing to Our Brains by Nicholas Carr that covers this stuff and points to research.

There's also the Wall Street Journal article by him called Does the Internet Make You Dumber?.

https://www.wsj.com/articles/SB10001424052748704025304575284...