WITH THE EXCEPTION of “Cars” — a commercial success but creative misfire — Pixar has exhibited an untarnished track record. Perhaps that’s why the company has been emboldened to undertake an endeavor as demographically audacious as “Up,” its 10th animated feature.

Although beautifully executed, designing the story around a widowed septuagenarian feels jarring — especially in the context of an animated film — and has already provoked plenty of armchair quarterbacking. It has also unleashed some of the thinly veiled ageism that permeates popular entertainment, which should make the rooting interest on “Up” rise above simply whether the film can liberate Disney from its box office doldrums.

As I recently observed, there has been subtle, mostly unacknowledged progress in juicy roles for actors old enough to receive AARP magazine, including much of the glittering “Damages” cast, the senior tier on HBO’s “Big Love,” and star turns by Ian McShane and Tom Selleck in NBC’s “Kings” and CBS’ “Jesse Stone” telepic franchise, respectively.

That said, because the 55 and older audience is considered dross when networks sell ad time –essentially the free gift one gets with a purchase — there’s scant incentive to mold them into three-dimensional shapes.

So while matters have tacitly improved for performers “of a certain age,” more often than not those who do appear are caricatures — horny grandmas and deaf old farts. The fact that some of them manage to shine (see Susan Sullivan, say, in ABC’s “Castle”) is usually more in spite of the material than because of it.

Of course, the 78-year-old lead in “Up” is both irritable and prone to turn-off-the-hearing-aid gags, so the movie is not immune to these tendencies. Yet barring the occasional welcome curve ball like Clint Eastwood’s “Gran Torino,” it’s a characterization with far more depth and heart than is readily found in major studio releases or network upfront presentations.

INDEED, the definitive twist on aging right now seems to reside in the style section phenomenon known as “the cougar,” described as an “older” woman (that is, around 40) dating a 20-something guy. Not only has this birthed a TV Land reality show by the same name but two separated-at-birth sitcoms for the fall, ABC’s “Cougar Town” and CBS’ “Accidentally on Purpose,” where dalliances with Courteney Cox and Jenna Elfman qualify as sexual grave-robbing. And there’s another May-December pairing (actually, more like March-June) on the CW’s “Melrose Place” revival.

Then again, motivated by the buzz surrounding “Gossip Girl,” the CW has constructed an entire lineup around the lives and loves (or at least fleeting hook-ups) of the under-25 set, becoming the TV equivalent of “Logan’s Run.” While there’s logic behind steadfastly pursuing a brand identity for a niche channel in this crowded environment, the netlet appears unduly determined to approximate the depth of MTV’s “The Hills” and its myriad spinoffs in a scripted setting.

ABOUT THE ONLY room for those over 40 on CW is limited to vampires who continue to look 25. It’s worth noting, too, that anyone outside the size-zero dress demo clearly has the wrong body shape for the web, whose programming at a glance is more hospitable toward the undead than the obese. Watching the upfront presentation flash by resembled “Girls Gone Wild” ads or an Abercrombie & Fitch catalog.

Contrast that with “Up” — where the younger character is a pudgy, awkward, lonely boy scout — and it’s no wonder the chattering class can’t quite figure out what to make of it. Nearly two months before the movie’s opening, the New York Times fussed over whether “Up” would sell tickets and move action figures, quoting Pali Research analyst Richard Greenfield saying, “We doubt younger boys will be that excited by the main character.”

That might very well be true, although reading the mind of younger boys is generally beyond my powers of perception — except when I’m waiting in line next to them at Comic-Con.

Still, for anyone who wishes that TV and movies were more uplifting in their treatment of considerably older boys (and girls), a happy landing for “Up” would be a pretty good place to start.