Jason Schwartzman - one of the voice cast in Fantastic Mr Fox - is a regular in Wes Anderson's films, but still isn't at ease with being a public figure, despite his membership of the Coppola clan. He talks to DONALD CLARKE

JASON SCHWARTZMAN - neat in a gleaming white shirt and sharp black suit - admits to being nervous. You could view this as an unlikely development. Since he first caught our eye as the precocious teenage intellectual in Wes Anderson's Rushmore, Schwarztman has cornered the market in characters who flatten neuroses with arrogance. He was at it again earlier this year in Judd Apatow's Funny People. I imagine Schwarztman suavely brushing away any inclinations toward nervousness.

"Oh no," he says. "I am on my way to a press conference and that just scares me. Then again, often I don't know I'm scared. When I've just finished doing a talkshow or whatever it's like somebody has just turned off the air-conditioning. I mean there was this constant hum of fear that I didn't notice was there until it was turned off."

This nervousness also surprises because Schwartzman - among the voice talent in Wes Anderson's amusingly peculiar Fantastic Mr Fox- emerged from one of the most influential families in the entertainment industry. His mother is Talia Shire, star of Rockyand The Godfather. His uncle is Francis Ford Coppola, one of the great directors. His cousins include Nicholas Cage and Sofia Coppola. One assumes that, from an early age, he has been coached in the art of being blasé about fame.

"Blasé? No, not at all," he says in his sweet, slightly deadened voice. "My family is anything but blasé. They are quite the opposite. They are even quite intense about listening to music or watching movies."

His mother enjoys a peculiar class of fame. Talia Shire never threatened to become an enormous star, but she did manage to appear in two of the most iconic films of the 1970s. She played Connie Corleone, the sensible sister who briefly goes awry, in her brother Frances Ford Coppola's imperishable The Godfather. A few years later, she turned up as the hero's unsophisticated girlfriend in Rocky.

When did the young Schwartzman realise his mother was famous? "I'm not sure. She's pretty shy and humble. And she didn't work a lot once I was born. But it must be amazing to be this person who has this appeal for people who saw Rocky, people who see her and shout: 'Yo, Adrienne!' I remember being little and we'd go to the mall and people would walk up to her and say how nice it was to meet her. I thought it was an amazing thing to be able to affect strangers that way. Very powerful."

But that loss of privacy can be a darn nuisance. Having all those Coppolas around must have prepared him for the business of being pestered when buying butter. The movie business is not always fun. "It is a whacked out business," he says. "That much is true. But all businesses have their downsides."

Schwartzman always knew he wanted to become involved in performance. He would have played in "a pit in an orchestra" if it meant he could work in the arts. Throughout his teens, he dabbled in pop music and continues to release the odd record now.

There is something very much of-its-time about Schwartzman's career trajectory. A slightly neurotic guy with a hip, somewhat woolly sensibility dabbles in music and other enterprises before stumbling into an equally blank, modish film director. Late 1990s quirk results.

That director was, of course, Wes Anderson. Schwartzman and the Texan geekmeister helped create one another's public persona in Rushmore and further developed the double act in The Darjeeling Limitedand, now, Fantastic Mr Fox. Even after meeting the nice, chatty, but definitely odd Schwartzman, it's hard not to think of the actor as a creation of Wes Anderson.

"We are comrades and we will always be comrades," he says. "I can't really say why that is." They do, indeed, appear to be brothers in arms - both slightly distant, both slightly affected. Yet, in an aside, Schwartzman admits that, on occasion, he wishes he had the sangfroid of George Clooney, his co-star - and father - in Mr Fox.

"Yes, I do admire people like George," he says. "He is so in-control all the time about everything. I wish I could have that too."

So how does he shake off all this tension and relax? "I am not a good chiller out," he says. "I find it hard to just sit and read. So I'll go on the internet. I'll talk to my wife. Maybe, I'll have a little gin." A little gin? Now there's something George Clooney could get onboard with.