Why can’t these rich kids behave?

Hollywood is a town that has always known how to feud. You do it behind closed doors or, if you must go public, you spend massive legal fees to do it in courtrooms or for free with angry words and nasty insinuations in gossip columns. (See: Eisner vs. Katzenberg, Ovitz vs. Everyone.) So what is it with the twentysomethings these days? The feuding of Young Hollywood has taken a tawdry turn lately, combining the nastiness of middle-school Queen Bee behavior with an ugly, menacing physical element.

As usual, at the center of things is Paris Hilton, the 25-year-old hotel heiress/singer/hamburger lover whose every step and misstep is tracked assiduously by camera-wielding opportunists.

This time, according to the Associated Press, Hilton and a former Playboy Playmate and “Dancing With the Stars” contestant, Shanna Moakler, tussled at a hot Hollywood nightclub late Tuesday. Hilton claims to have been verbally assaulted, then punched in the jaw by Moakler, who claimed that Hilton’s ex-boyfriend, Stavros Niarchos, then bent Moakler’s wrists and poured a drink on her. Earlier, the celebrity gossip website TMZ had posted a video of Ms. Hilton making out with Ms. Moakler’s estranged husband, former Blink-182 drummer Travis Barker, at a crowded club. Casus belli? Apparently so.

“It does seem there is a rash of new stars who are really behaving like high schoolers,” said Harvey Levin, TMZ’s managing editor.

“People who get famous really young are in danger of having their growth stunted. They graduate from high school and live in this artificial world and they don’t have to mature the way other people do.”

Just last May, another young socialite, Brandon Davis, the 29-year-old grandson of oil baron Marvin Davis, was captured by video cameras as he walked with Hilton along a Hollywood street spewing vitriol about the actress Lindsay Lohan, with whom Hilton was “feuding” at the time. His outburst, which he blithely directed at the camera, was both amusing and extremely vulgar, remarkable mostly for its use of the infelicitous word “firecrotch,” which sounds like an insult that should be uttered on “Deadwood,” not on the streets of 21st century L.A.

Perhaps most telling, though, was Davis’ reference to what he apparently considers Lohan’s most egregious shortcoming: “She’s worth about $7 million, which means she’s really poor.”

This sort of crass behavior, and the increasingly threatening undertones being taken on, is unsurprising to Marin County psychologist Madeline Levine, who specializes in the problems of affluent teens and their families.

“Upper-middle-class kids who are the alpha dog in junior high school sort of have this trajectory of aggression,” Levine said. “One would expect the arc to level off, but they continue to get more aggressive.”

Research on children up to 18 has demonstrated this phenomenon, she said, “and my guess is the only reason we don’t know for sure about 25-year-olds is that no one has looked at them from a research point of view.”

Levine has just written “The Price of Privilege,” a book about how extreme materialism and parental pressure to achieve are creating a generation of unhappy young adults, adrift in the larger world, where true happiness, it turns out, does not derive from money, gadgets or high test scores.

The twentysomething brats of Hollywood, because they are ubiquitous and create so much fodder for paparazzi, the Internet and celebrity-oriented magazines, are the latest symbols of affluence run amok. “They are representative of the fact that stuff matters more than people, that competition matters more than cooperation and individualism matters more than reciprocity,” Levine said. “Look at the way she carries her dog around like an object,” referring to Hilton’s doggie accessory.

The impulse to get attention -- any attention -- is perfectly reasonable in a narcissistic 13-year-old. But it’s not so attractive in a twentysomething, said Rosalind Wiseman, author of “Queen Bees and Wannabes,” the bestselling 2002 guide aimed at parents helping girls survive the mean streets of adolescence. “Getting more attention, no matter what, has become the positive consequence” for these obnoxious young adults, Wiseman said. “You’re always looking for the next thing to do to get more attention, always upping the ante.”

Harvey Levin sees it the same way: “The ones who act that way get the most publicity, and it gives permission for others to do the same, because it almost seems like the cool thing to do.”

When people like Hilton and Moakler turn up in a police station complaining about each other, Levin said, “I am assuming that the desk sergeant probably looks up and says, ‘Oh, it’s you again.’ ”

robin.abcarian@latimes.com