In her last TV incarnation for seven seasons as “Supernanny,” British import Jo Frost arrived at American homes in a black, London-style hackney cab and set about helping the fried parents of manic, misbehaving toddlers establish some order and discipline. Frost dressed in a stern uniform — children were clearly intimidated — and dispensed the toughest sort of love; mostly she taught parents how to say no.

People with and without children (especially people without children) drew a certain smug satisfaction from the show, dovetailing nicely with the Internet’s troubling talent for gang-lecturing people right where it hurts most, in matters of family lifestyle, entitlement and parental shortcomings.

After a short absence, Frost has retired the supernanny shtick and returns Tuesday night in an admirably resolute but occasionally difficult new TLC reality series called “Family S.O.S. With Jo Frost.”

Here, the emphasis is on addressing a more prolonged set of child-rearing dysfunctions that have produced yard apes and terror teens. In addition to a whole lot of bratty “[bleep] yous” and slammed bedroom doors, Frost is drawn to root causes: marital spats, addiction issues and verbal and physical abuse. The whole gift basket.

Her first assignment takes her to Huntington Beach, Calif., where 55-year-old Don and 49-year-old Julie have made a disastrous attempt to blend families. Spiteful teenagers seem to be slumped in every corner here, hissing four-letter words at one another and their parents, like a small army of Linda Blairs.

Jo Frost. (George Lange/TLC)

“I’ve been told [that] if I can’t help this family in one week, they will divorce,” Frost tells her viewers, and while that may provide a narrative hook to hang this on, it’s hardly an incentive to keep watching. “I don’t feel like this is real,” fumes 17-year-old Chad, who’s fighting a drug and alcohol addiction. “[It’s just] for some B.S. TV show.”

Two points for Chad, but minus 10 points for storming off. Frost is staying put, as is her TV crew, so everyone better shape up. Sixteen-year-old daughter Amber sneaks out to a booze party; Frost forces Julie to discipline the girl when she returns and you might want to click the mute button while the lovely Amber screams it out.

The film crew, meanwhile, has a blunt taste for the ironic, zooming in on Julie’s decorative penchant for delusional tchotchkes: “Love is Spoken Here,” reads a wall hanging. (“I HATE YOU SO MUCH!” Amber screams again from her bedroom.) “A Daughter is a Special Gift From God.”

For all its noise and uncomfy moments, “Family S.O.S.” is relatively genuine stuff, especially for the current incarnation of TLC. Viewers who know Frost’s previous work will have no trouble believing that she cares about the outcome and sincerely wants to help these families patch thing up. When they cry, she cries — and if it’s all an act, well, it’s a good act. A different episode takes Frost to another Los Angeles suburb, where a husband and father is confronted with the fact that he avoids parenting duties and has been borderline abusive to his brood, especially the mentally disabled son who struggles with toilet training.

When I say “This is hard to watch,” you are absolutely correct to thunder back, “Well, then why do you watch it?”

Because it’s life. Some of us are just endlessly interested in other people — more than we are drawn to nature documentaries or singing competitions. We’re not snoops so much as amateur sociologists. When Frost walks into the house, she asks to look around, so she can see where the bedrooms are and see where various family members spend most of their time. She’s interested in kitchen tables and photos on the wall. The difference between Jo Frost and Gladys Kravitz — the nosy neighbor from “Bewitched” reruns, who remains fixed as a cultural symbol of disrespected privacy — has something to do with empathy; a curious and often heartbreaking empathy.

The scowling teenager with his arms folded is absolutely correct: Much of what’s happening here is affected and determined by the presence of Frost and her TV crew. And yet, for those of us who want to know more about the family dynamic — in its entire spectrum, from comfort to estrangement — “Family S.O.S.” is a worthy endeavor.

Is it top-quality television? Compared with “An American Family,” no; but compared with shows about spoiled-rotten gypsy brides (a recent TLC fixation), you bet.

Family S.O.S. With Jo Frost

(90 minutes) premieres Tuesday

at 9 p.m. on TLC.