Adam Sandler’s comedies are not “dumb fun”; maybe that’s why they’re not in critics’ favor. Sandler’s hilarious new film Jack and Jill (in which he portrays both male and female fraternal twins), brings to mind the great line that Ernst Lubitsch’s classic 1946 female plumber comedy Cluny Brown “upset people who didn’t like to admit they have plumbing.”

In Jack and Jill, Sandler looks at sibling rivalry without that acrid love of dysfunction now so popular on TV and Broadway. It’s obvious that Los Angeles ad exec Jack and his hefty, homely, still unmarried sister Jill who visits from New York will mend their rift but the fun is in watching the healing process. The film’s comedy (as in adult petulance and coach potato behavior) shows the depths of kinship—similarities siblings can’t help sharing but learn to accept in themselves. And Sandler’s always protective—as when Jack insults Jill but warns “I can say that because I’m her twin.”

All Sandler’s best comedies (Grown Ups, Bedtime Stories, I Now Pronounce You Chuck and Larry and the great Spanglish) are really love stories. He explores affection without the class and gender guilt Judd Apatow hides behind (such distraction scuttled Apatow’s grandiose Funny People). Sandler’s willingness to appear “dumb” is what makes his films so cathartic. He thrives on being unembarrassed—the key to classic comedy going back to the Greeks.

Sandler, of course, always goes back to Jewishness. He may be the least ethnically abashed Jewish film comic outside the Borscht Belt which is Jack and Jill’s natural strength. Jack’s self-consciousness about Jill is rooted in Jewish comics’ proverbial self-deprecation (that’s why the twinship premise). Jill’s large features, gaucheness, petulance and unsophisticated ways are not anti-Jewish traits but the qualities that insecure, social-climbing ethnic groups usually evade.

In Jill drag, Sandler looks like young women you see on the subway; she’s a homely archetype Fanny Brice, Judy Canova and Martha Raye made popular. (Eddie Murphy also mastered this comic affection in The Klumps and Norbit.) Credit Sandler’s subtle feminine caricature—especially in dancing and athleticism—that avoids making Jill a clownish grotesque like Tyler Perry’s Madea. Perry’s drag is based in parodying ethnic shame. In Jack and Jill Sandler embraces rude, crude and earthy in ways that Tyler Perry wouldn’t dare. Or will he ever?

Sandler’s real dare is to defend ethnicity—not piously but through comedy that has social and political effect: When Jack’s WASP assistant (Nick Swardson) boasts that he’s almost Jewish because “I’m an atheist,” Jack looks nonplussed. Yet, Sandler isn’t. His comic introspection has a moral core. Appreciation of roots and background is what gives the film’s overlong but uproarious Al Pacino subplot its basis—it’s both crazily romantic and a professional salute. That’s because Sandler knows how our plumbing works.