Poop jokes will always be funny. They are dumb and disgusting and probably harmful in some way and yet we can’t get enough of them. File them under “juvenile” along with sex jokes, race jokes, cartoony violence and bad puns; they may be singlehandedly responsible for the decline of Western civilization, but, when they are done right, we cannot resist the raw power of their giggle-inducing influence.

Now, put all that in the mind of a nine-year-old girl who happens to be trapped in the body of a 39-year-old woman, and you have Sarah Silverman. Put Sarah Silverman in a surreal mashup of sitcom and children’s show – and toss in some goofy musical numbers for good measure – and you have the third season of “The Sarah Silverman Program.”

If you are familiar with Silverman’s stand-up comedy, or at least with the basic premise of her schtick – immature and self-centered Jew pokes vicious fun at everything, vilest lines delivered with cutest faces – then you already have a pretty good idea of her character (well, caricature) on the show.

Most of the action centers on her shenanigans as this character. The show follows a 30-minute television show’s traditional plot/subplot formula, with the subplot involving one or more of the minor characters. Tonight: does Sarah have a penis? How will Brian and Steve escape the ghost of their neighbor?

When the Daily Collegian caught up earlier this week with Sarah’s older sister and castmate, Laura Silverman, she mentioned that this season, we might finally start to see a departure from that formula, or at least an inversion: “All of the supporting characters get a lot more developed this season. There’s a lot more storylines involving the other characters.”

Laura described her own character, a fictionalized version of herself, as “sort of sweet and stupid, but maybe not as stupid as she seems. Maybe.”

In the show, Laura is Sarah’s younger sister, but their relationship is at least partially based on Laura’s childhood doting on her little sister.

“I just always thought she was so cute. And I just – I loved taking care of her and, you know, doing things for her.”

The made-for-television version of this relationship, exaggerated and extended into adulthood, is pretty much what allows Sarah to continue to be the way she is. Since she is too lazy and immature to ever hold a job for longer than an episode, Laura covers her rent (and all other expenses). This is the engine for a great deal of the plot; Sarah does something terrible, Laura covers for her, Laura’s husband Jay (Jay Johnston, “Mr. Show”) insists that Sarah take responsibility, Sarah screws that up by doing something terrible, and so on.

The show’s puerile sense of humor may be inspired by Sarah’s stand-up act, but according to Laura, much of the credit belongs to executive producer and head writer Dan Sterling.

“He [Sterling] thinks of the poop jokes. In a really intelligent, brilliant, very highbrow way, of course. He has a very important job, writing poop jokes,” said the elder Silverman.

She sounds like she’s joking there, but went on to assure us that “I think it’s really smart, actually, in the secretest of ways.” And it’s true – under all the layers of poop, there’s a sweet, delicious kernel of genius. But the real secret is that you don’t have to dig to get at it. The poop is the best part.

Fortunately, the high-minded aspect never gets in the way of the basic – and base – humor of the show. This has been a stumbling block for a lot of very smart comedy writers in the past. As Laura said, “It’s not easy to be really smart about being stupid. A lot of people try, and few succeed.”

“The Sarah Silverman Program’s” third season debuts tonight at 10:30 p.m. on Comedy Central, and rest assured, it succeeds heroically. Think withered baby penises.

Sorry.

Garth Brody can be reached at [email protected].