The kid is bilingual, he speaks both Czech and English as a mother tongue, although he started by speaking mostly Czech. Czech has the advantage that everyone speaks it in this country, but (American) English has the advantage that Daddy speaks it, and more importantly, so does Batman. Now that he's on the cusp of five, he's become a real connoisseur of language--totally fascinated by expressions--and it's pretty amazing to see him pick up on these things. Czech simply can't keep up in the cool phrases department. A few minutes ago he was watching Planet 51 and made me rewind the phrase, "...not full of sea-monkeys dancing to the oldies," five time because he thought it hilarious even if he didn't fully understand it. This also entailed explaining what "oldies" and "sea-monkeys" are.
The vocabulary my kid has picked up from watching such "mindless crap" has made my wife a believer. It won't be that long before my kid will have a better English vocabulary than she does, which is pretty amazing for a four-year-old living in a country where his only exposure to English is me, TV shows and the occasional long distance conversation with grandparents or our ex-pat friends (also my wife and I speak English together at home).
This is where I get deeply skeptical of the naturalistic ideal or hippie-dippie aspects of Paleo/Primal/etc mindset, or what Kurt Harris calls Paleo reenactment. I've seen Paleo-type bloggers complain about things like running or walking with mp3 players. When I go for walks I usually listen to podcasts and frankly see nothing wrong with it even if my HG predecessors didn't own a Walkman. Hell, I had a paper route for years and spent many tedious hours folding and throwing newspapers at ungodly hours with nothing to listen to but AM radio. This is why I still have a burning hatred for Stevie Nicks. I would've loved to have an MP3 player where "every song you've ever heard, or will ever hear or will ever be written can be put on that thing," as Patton Oswalt put it, yet cost less than 100 US monopoly money dollars.
Now I could point that stories about mythic archetypes have been with us forever, told while sitting around the fire talking of Odin or Coyote the Trickster or whatever, If I wanted to put some sort of What Would Grok Do spin on this, and I actually think there is something to that. What is Batman but a flawed demi-god who drives a really, really cool car?
I've written before how I consider educational (and especially moralistic) TV to be worthless as an educational tool and worse than useless by people who think these shows have some sort of intrinsic merit. But now I'm going to go even further and say, based on my n=1 parenthood experience, that it's the kind of television made for pure entertainment that can actually have the merit of being educational.
So my advice is, if you have a bilingual kid and you want them to improve their language skills, let them watch whatever they find most interesting--this will probably not be a show created by education "experts". But why should this stop at bilingual kids? I think that homo sap children in general, with their big ol' brains, naturally gravitate to the more complex and subtle, that there's a natural urge to unfold one's mental wings. This is probably accelerated by older sibling's perceptions of what is cool, and coolness usually entails a lot of subtle signalling that is (purposefully) opaque to other groups like parents or non-hipsters--again a drive towards more subtlety and complexity.
This is not to say I'm going to be enrolling my kid in a Sudbury School or homeschooling him with Michael Bay movies. There's a time for having stuff shoved down your throat by your parents, and that time is when your parents can beat you up. Seriously, I'm not even close to believing that all learning should be "fun". We've all known people with immense talent that was immensely squandered for lack of application and discipline, it's practically a cliché. There is the rote aspect of discipline to any enjoyable skill, be it tennis, mathematics or dwarf tossing. And while guys like Richard Federer and Aragorn may make such things look easy, there were countless hours of tedious practice behind their effortlessness.
But if your kid is going to watch some television (and why shouldn't they?), I think shows like The Justice League whip Dora's little ass.