Jackson Nicoll and Johnny Knoxville in Bad GrandpaJACKASS PRESENTS: BAD GRANDPA

This might surprise a grand total of none of you, but Bad Grandpa - which also goes by the more telling title Jackass Presents: Bad Grandpa - isn't much of a movie. The first Jackass release to feature an actual narrative, and actual characters, in place of the usual parades of comically vile, violent challenges and stunts (though there are a few of those, too), director Jeff Tremaine's road-trip slapstick is mostly shapeless and certainly obvious, and nowhere near as hilarious as you want it to be.

Yet it's also a continually interesting and, in the end, rather sweet sociological experiment reminiscent of Borat, but a Borat without the mean-spiritedness. If Sacha Baron Cohen's outing, with its Candid Camera-style employment of "real people" clearly not in on the joke, reveled in displaying how crass and ignorant Americans could be, Tremaine's suggests just how tolerant and polite we can be - and given the circumstances presented here, that's apparently mighty tolerant and polite indeed.