Today on "Jerry Springer": "Mistress Mayhem!" -- Eric wants to come clean to his wife today. He's been having an affair with their neighbor: a gay prostitute! And tomorrow: "Honey, I'm Really A Woman!" And today on "Sally Jesse Raphael": "Broken Promises" -- Sally talks with people who have broken the trust of their loved ones. And tomorrow: "Cheaters Caught on Tape!"

Yes, it's trash TV-daytime television talk shows that revel in the worst the human experience has to offer.

Why do they do it -- the producers, the hosts and, most surprisingly, the guests? Laura Grindstaff, UC Davis assistant professor of sociology, spent several years finding out.

Grindstaff interviewed more than 80 participants, attended live tapings and worked as an intern at two nationally televised talk shows: one that she characterizes as "trashy"-a show like "Jerry Springer" -- and the other "classy" -- a show like "Oprah." (To protect the anonymity of their staff members, she doesn't name the shows.) She learned about how and why producers elicit tears, shouting matches and fistfights from their guests, why the guests agree to participate and the supporting roles played by the audiences and the experts. She also learned much about what these shows say about the mass media and American society and culture in general. Grindstaff shares her findings in a book, The Money Shot: Trash, Class, and the Making of TV Talk Shows.

Key to a talk show's success, Grindstaff found, is that moment of conflict, the dramatic climax when guests lose control emotionally or physically -- what she calls the "money shot," borrowing a term from pornography for another kind of climax. Topics and guests are chosen, shows structured and guests prepared to maximize these emotional climaxes.

And guests are prepared to deliver, Grindstaff said. "Most do know in a general sense what they're getting into." They have seen the shows, and they know what's expected.

But why do they do it? The classy reasons, Grindstaff found, are to champion a cause or educate the public. Trashy reasons include the excitement of being on TV, the free trip to the city, revenge, attention and public validation. "Everybody wants to feel that what they do matters," said Grindstaff. "They want validation, and media coverage is a very powerful form of validation in our culture."

Though the producers may get what they want and the guests often do, too, the unbridled excess isn't without victims.

These shows perpetuate a vulgar and tasteless stereotype about the poor and working-class people, Grindstaff points out. "It's a vicious image of these people in our culture, and one that goes unchallenged." But she doesn't just blame the media.

"We could take the media to task for turning everyday lives into circus sideshows, but we must also blame the society that gives this class of people few other outlets for being seen and heard."