‘Bad Grandpa’ hits the sweet spot

I pride myself on demonstrating a level of decorum, good taste and professionalism for the larger part of my waking hours: social gatherings, parent-teacher conferences for my children, meetings with my bosses and (for the most part) my staff and colleagues. I can talk cogently and respectfully, and feel comfortably literate on a number of subjects.

So why is it that the folks from “Jackass” can turn me into a snickering, snorting child with some of the most base, puerile, and just plain stupid humor? It’s a disease from which I’ve apparently long suffered, unable to outgrow it despite my progression in age. In what I can only identify as the Stooges Gland, there is some sort of primordial sliver of my brain that has ceased to develop and responds to such groin-kicking, senior-swearing shenanigans as though they were the height of hilarity. Needless to say, “Bad Grandpa” hits the sweet spot. Johnny Knoxville goes solo for this one, jettisoning the "Jackass" on-screen crew (but keeping it in the title, which is officially “Jackass Presents: Bad Grandpa”), but spinning off the old man character that was featured in the first few “Jackass” films. Instead of a series of skits, this time the filmmakers try to fashion an actual narrative out of a succession of gags.

Knoxville, behind layers of liver-spotted latex, plays Irving Zisman, a lecherous, libido-driven old coot who’s just been informed that his wife has died, news he greets with exuberance. But before he can start celebrating at the local strip joint, old Irv is saddled with his 8-year-old grandson Billy (played by Jackson Nicoll), whom he must drive across country to be with his lout of a father. The plot is but an excuse to place the two in a number of real-life situations meant to stun, shock and mortify common folks while hidden cameras roll to capture the shock and guffaws. Structurally, it’s more akin to Sacha Baron Cohen’s “Borat” than the previous “Jackass” features, but the whole affair feels much more good-natured than Cohen’s creations did. The reason for this is that much of the humor is directed at Knoxville’s Zisman, and the camera captures more stunned reactions than subjects making fools of themselves.

Another element that grounds the film is the performances of its leads. Knoxville not only looks the part, but nails the vocal inflections and all the movements (even the most inappropriate ones) of the octogenarian. His performance is elevated by his obvious affection for his gifted little costar, Nicoll. The kid has comedic chops and possesses an honesty and sweetness that give his role an unexpected authenticity (even when he is at his most manipulative).

That sweetness is at the core of “Bad Grandpa.” Even as he’s scaring, confusing and frustrating his victims, Knoxville never seems to be doing any of it with malice or ill will, and the film provided more laughs than I have had at the theater since this summer’s “This is the End.”

In essence, even though I entered as a dignified adult, “Bad Grandpa” was like a pure eye-poke-face-slap combo to my Stooges Gland.