In 1971, Edie Sedgwick, the subject of Jean Stein’s last book, died in Santa Barbara of an overdose of alcohol and barbiturates. That same year, Jennifer Jones, one of the principal figures in Ms. Stein’s new “West of Eden,” staged a theatrical suicide attempt by walking into the ocean in Malibu, with good reason to expect she would be rescued. She was. She lived until 2009, surviving a troubled daughter, an even more unhinged son and two very rich husbands, David O. Selznick and Norton Simon. Even when running out of money, she insisted on spending $500 a month to have her sheets pressed.  Welcome to Ms. Stein’s Southern California. Ms. Stein is the daughter of Jules Stein, founder of MCA, not one of show business’s most fabled figures but at one time among its most powerful. She grew up on a Beverly Hills estate grand enough to have become part of Rupert Murdoch’s real estate collection. Her peers were the children of Hollywood royalty. She is unusually well positioned to describe the bad behavior of Hollywood’s ruling class.  Despite its provenance, “West of Eden” is strangely unfocused, especially when compared with Ms. Stein’s indelible “Edie.” Both are oral histories, but “Edie” (1982) had a mesmerizing focal point in Sedgwick, the Brahmin heiress turned It Girl turned casualty of her own frailty and ambition. It also had a clear time line, a spectacular cast of characters and the editing help of George Plimpton. And it flowed without interruption, whereas “West of Eden” is chopped into a few chapters about seemingly arbitrarily chosen families. They do have certain things in common. Self-made patriarchs, money to burn, messy family trees created by multiple marriages, neglected children, rampant jealousy — and the inevitable craziness turns up everywhere.  The craziness prize goes, hands down, to the obscure story of Jane Garland; it seems to be this book’s real discovery. It’s about elaborate efforts to keep Ms. Garland, the daughter of a real estate executive, in her family’s Malibu house and out of a psychiatric hospital. The doctor-recommended solution to wrangling Jane was hiring good-looking young men to be guards and escorts. Shrinks called the shots for many people here. Some Garland escorts, like the artist Ed Moses and the curator Walter Hopps, would go on to become much more famous than the book’s so-called celebrities.  “West of Eden” includes only a terse set of biographical notes, which is an extreme annoyance; it needed the full biographies, genealogical charts and abundant illustrations that were so necessary to “Edie.” This book is so stingily illustrated that you must read halfway through its Jane Garland section before finding out what Ms. Garland looked like — and this after reading plenty of physical descriptions of her. And it’s positively criminal to include cheap black-and-white copies of Salvador Dalí’s vibrant, sadistic color portraits of Jack and Ann Warner.  There are few clues to the roots of Jane’s problems, though we learn that her father was abusive. (A daughter by his first marriage says he kicked his wife while wearing golf shoes. “I think that’s very unfair when you do that with your golf shoes,” she says.) Jane’s wild behavior — throwing ice cream, doing half-naked headstands, setting the house on fire — is sympathetically described by creative men who appreciated her. In recalling how frightened he was when Jane would try to strangle him, Mr. Moses simply says: “We all have those stories.”  But nobody has a sympathetic word for Jennifer Jones. She is used to epitomize the kinds of horrors that died with Hollywood’s golden age. Seen through the eyes of a younger generation, she is recalled as having virtually abandoned her two sons by the actor Robert Walker once she married Selznick and then losing interest in Mary Jennifer, her daughter with Selznick, by the time the girl was about 7.  She spent much more time with her psychiatrist than with Mary Jennifer, whose first daily glimpse of her mother always came at 6 p.m., after Jones had been out horseback riding. Mom greeted her carrying a whip. When the Selznicks hosted parties, if the book is to be believed, the hostess put in her first appearance two and a half hours after guests arrived and wore three different outfits during the time that remained.  Jones provides the book’s best examples of dementia, Hollywood style. One is, “I miss him, were we ever married?” (They weren’t. He was her psychiatrist.) Another, about someone’s effort to return a lost handbag to her: “No, I’m not taking it. It doesn’t match my outfit.” But this is only an extension of the narcissism that the book’s Mrs. Mogul types share, however miserable it makes their children. (Forget the stepkids. Their stepmothers did.) To be fair, being Mrs. Jack Warner couldn’t have been easy. He is seen here in a photograph with the wonderful caption: “Jack Warner, astride a lion, surrounded by yes men.”  The Warners are the most glamorous bunch in the book, as well as the most spiteful. Ms. Stein has dug into the dirty trick by which Jack wrested Warner Bros. away from his brother, Harry; into Jack’s naming names before the House Un-American Activities Committee; and even into the size of the Warners’ bomb shelter, which thoughtfully included room for the staff “because you couldn’t let the servants die — they were hard to find during the war.”  The book also describes the sale of the Warner estate to David Geffen — and here, as in other places, some fact-checking would have been nice. The Warners’ daughter describes Mr. Geffen’s showing the house to Steven Spielberg, who was given a leather-bound screenplay of a James Dean film that dated from around the time the director first came to Hollywood. Mr. Spielberg may have been a boy wonder, but his age was in the single digits when Dean’s films were released. And the book describes Jane Fonda and Roger Vadim’s much-chronicled Malibu Beach party as having occurred in 1963. So she has the Byrds playing “Mr. Tambourine Man” before it was written.  No Hollywood book would be complete without snobbery, and this one has its share. A chapter on the Doheny family, known for its oil fortune, sniffs at “There Will Be Blood,” with Daniel Day-Lewis playing a character somewhat based on Edward L. Doheny, the patriarch. “The actual story itself is so much more interesting than anything they might have come up with,” one Doheny says. And Ann Warner’s butler/chauffeur insists on pointing out: “I come from a very distinguished Spanish family in Chile, much better than the Warners.” If only everyone in this book spoke as unguardedly as that.  Illustrated. 334 pages. Random House. $30.  A version of this review appears in print on February 5, 2016, on page C26 of the New York edition with the headline: Listening to Hollywood Not-So-Confidential. Today's Paper|Subscribe
In an oral history, Jean Stein chronicles the bad behavior — and worse — of an old ruling class.