The thesis of Everything Bad is Good For You is that there is a ‘Sleeper Curve’ in popular media that is actually making us smarter, not dumber as intuition would suggest (due to catering to the lowest denominator). The book discusses relevant topics such as gaming, TV, internet, and film (cinema); bascially what many of us would call as hobbies.
Parallels are drawn between TV series from the 50s to popular works of today such as Lost and 24; and it is suggested that these activities are improving our cognitive skills. Perhaps the author is simply finding a reason to allow him to watch all these shows!
The second proposition is that our IQ is increasing, however the argument in this respect is not as convincing. Overall however, it was an interesting (and very quick!) read.