A new book argues that it does. The New York Times has what appears to be an excerpt.

For decades, we've worked under the assumption that mass culture follows a path declining steadily toward lowest-common-denominator standards, presumably because the ''masses'' want dumb, simple pleasures and big media companies try to give the masses what they want. But as that ''24'' episode suggests, the exact opposite is happening: the culture is getting more cognitively demanding, not less. To make sense of an episode of ''24,'' you have to integrate far more information than you would have a few decades ago watching a comparable show. Beneath the violence and the ethnic stereotypes, another trend appears: to keep up with entertainment like ''24,'' you have to pay attention, make inferences, track shifting social relationships. This is what I call the Sleeper Curve: the most debased forms of mass diversion -- video games and violent television dramas and juvenile sitcoms -- turn out to be nutritional after all.

Or else they've made us all so incredibly stupid we don't even know what smart is anymore. One or the other.

[via MetaFilter]

UPDATE: Take, for instance, Johnson's much-vaunted episode of 24. I love 24; I watch it every week. But it certainly isn't making me any smarter.

How does 24 accomplish its deep critical work? By

a) stereotyping nearly every character
b) constantly violating believability, including its own established rules and conventions
c) reminding its viewers of the current plotline with at least five minutes of reintroduction and reexposition every single week
d) completely retconning the plotline every five episodes, dropping entirely almost every plot thread that came before.

Seriously, I have nothing against junk culture, which I sadly consume as much as everybody else -- but if you want something that'll make you smarter, read a book. I recommend Among the Missing by Dan Chaon.

UPDATE 2: Uh, or the first issue of Backwards City Review, which is guaranteed to make you smarter or your money back. (This is not a guarantee.) Order it today.