The image of Christina Ricci, as an actor of arresting darkness, hasn’t had much of an airing lately – for the past few years her output has been confined mainly to voiceovers and guest appearances in TV shows. As a result, perhaps, the 31-year-old has not aged in the public eye; she appears suddenly in a restaurant in Brooklyn, still child-sized, eyes not quite to scale, with that expressionless gaze behind which, one imagines, seditious thoughts circulate. Over the course of lunch, she will by turns be giggly, friendly, enthusiastic, monosyllabic and studiously anodyne. It is like watching someone page through the ringtones of human behaviour. “I’m an actress,” she says, “we constantly let things out. I can live with that.” If there’s a Ricci persona, it is in transition.

She is in New York temporarily to film Pan Am, the perky drama set in the heyday of the iconic air hostess. (The Pan Am uniform was among the most popular costumes in the US this Halloween.) It takes advantage of the Mad Men craze, although in the writing is more like Gossip Girl – bubblegum bright, with strong performances from her co-stars, little-known actors Karine Vanasse and Margot Robbie. Ricci, the only well-known name in the cast, is the “interesting” one, as evinced in the first 10 minutes by her name-dropping Hegel. Later this month, she and the rest of the production will find out if the show has been picked up for a longer run. In the meantime, life carries on in the apartment the studio rents for them in Brooklyn.

Her old attitude, says Ricci, was one characterised by a “defensive sarcasm”. There were rumours that some of the more obnoxious things she said in public put studios off using her for a while, but she doesn’t think it hurt her. In interviews at least, it has been replaced by a more conventional approach to publicity, so now Ricci says things like, “I’m so excited to go to work! I guess I’m a workaholic! I love it, it’s like my drug!” and, “My career’s gotten me this far, there have been ups and downs but things always happen!” etcetera, although there is still something brittle about her. It’s partly her voice, which has an awkward pitch to it, and partly her sudden jumps in register. She grins and says brightly she hopes Pan Am will get a longer season, but if not she will return to her house and her single life in LA.

It must be strange for Ricci to be among the oldest of the cast members, having for a long time been the youngest on set. She made her first film, Mermaids, when she was nine years old, after a year or so of TV work and having been discovered in a school play in New Jersey. A series of roles followed – Wednesday Addams in The Addams Family, Wendy in The Ice Storm, Dede in The Opposite Of Sex – all of which played on Ricci’s reputation as alternative and quirky, a female Johnny Depp. Since outgrowing teenage angst films, there has been less scope for her in mainstream movies, although she was very good in the Oscar-winning film Monster, in which she played Selby, girlfriend of Charlize Theron’s murderous Aileen Wuornos. In any case, she finds herself at 31 a veteran in a cast full of twentysomethings. “At first I was like, oh God, it’s so weird, because for years I was the youngest, although apparently I don’t act my age at all. No one can tell I’m any older. I just remember it happening gradually – so the PAs would get younger, and then suddenly the department heads were younger than me, that was weird. But now I’m used to it. I’ve come to terms with it. I’m an adult and I have to deal with that fact.”

She is still in touch with Winona Ryder, her co-star on Mermaids. “I know her and like her; I have affection for her. She’s an icon.” She’s a cautionary tale, isn’t she? Ricci gives me the first of several unblinking death stares. “Not at all.”

The nearest she came to going off the deep end was in her early 20s, when she got her hands on the money she had made as a teenage star. “I don’t come from money,” she says. Ricci is the youngest of four and it was partly to entertain her siblings that she went into showbusiness in the first place. After appearing in the school play, one of the other parents in the audience suggested to Ricci’s mother that the seven-year-old Ricci might be suitable for TV work. She was perfect in that she was small for her age, so could play younger than she was, but with the reading ability of an older child. “My brothers and sisters bullied my mother into letting me make the decision. And they were so into it – they thought it would be hilarious, to see me on TV. And I was like, sure, I’ll do anything to make you guys laugh.” After nine months of auditions, she got her first commercial. Three months after that, she was cast in Mermaids.

It never felt like work, Ricci says. It turned out she had a disposition exactly suited to hanging out on set with people much older than her, taking instruction. “I’ve always loved this. I always knew that I was kind of bored; the regular life of a child didn’t fit me. I wanted to work. I wanted to be utilised. I was always a really great set kid; I always wanted to be a member of the group. I wanted to do my best.”

It’s an odd thing to say: “I wanted to be utilised.” Wasn’t she intimidated by the adults around her?

“No. I would just think, this is a great opportunity for me to watch and learn.”

The thing you wonder about former child stars is what it was like for them to choose, or to have chosen for them, a career before they were capable of making such a choice. “Right,” snaps Ricci, dispensing the second death stare, “but I hadn’t chosen a career. It was always something that me and my family had said I would keep doing until I didn’t think it was fun any more. And then when I was about 14 I was like, no, I think I want to carry on doing this for the rest of my life.”

That was the age at which she decided to send herself to therapy. (Why? “Me and my sister have always been very curious and read a lot about women’s issues.”) Ricci’s father is a psychiatrist who promoted primal scream therapy, treating patients in the family basement in New Jersey, so that screams would issue up into the kitchen, where they went largely ignored by the rest of the family. It’s almost too good a detail, given Ricci’s early gothic performances. In the past, she has described her father as a difficult, unbending man, sensitive to the point of paranoia, with whom she confirms she is no longer in touch. Her parents are divorced. She will not speak publicly about her father now. It is her mother and her elder sister whom she credits with saving her from spiralling out of control in that brief period when she first got access to her earnings. “I thought it was hysterical when I finally came into money. I thought it was hilarious that I had money, which is, I suppose, not the kind of attitude you should have. I couldn’t really take it seriously. So I made all the mistakes that people make. I had a ridiculous car. I bought way too many clothes.”

What was the car?

“For a while I had a Porsche, it was really nice. It was leased. But you go through all that, growing pains, and then you move on.”

Her siblings would visit her on set, particularly her sister, the next one up in age, a teacher. She is the only role model Ricci has, she says, “because she deals with her life with a lot of grace. She always knows the right thing to do.” Her mother was also very grounded, she says and “taught me a lot of great tricks and attitudes that protected me. I have a sense of my friends and family. I keep myself fairly closed off from what’s going on in the business. It doesn’t interest me.”

She won’t read her own reviews (“There’s no point. It’s already done. You’re always going to hold on to the bad thing and forget the good thing”), which in the case of films like Black Snake Moan and Prozac Nation is just as well. She can watch her own performances with a critical eye without causing herself too much pain – “I can be, ‘Oh, maybe I shouldn’t make that face again’ but I’m pretty good at being objective about it” – although she has battled in the past to keep her weight down and remain healthy at the same time; at 5ft 1in, she is tiny and frail-looking.

The weirdest thing about early fame, she says, is the recognition. Not from the public – she tries not to pay too much attention to whether she is, or isn’t, recognised on the street, or to read it as a barometer of how her career is going – but the fact of having had, since a very young age, to give an account of herself. A large part of Ricci’s early reputation came from what she would say during interviews; self-consciously shocking statements such as, “I’m not afraid to die” and, “It’s such a natural thing to have sex with [your parents].” Although she says now, “I don’t think anything I said was really dark. I wasn’t running around like Marilyn Manson.”

For the first time in the interview, she becomes properly animated: “When I was younger, a lot of the strange things I said were based on the fact that I was so aware of how weird it was. People were asking me questions and I was like: I’m 17! I have nothing of value to add. I haven’t lived a life yet; I can’t tell you how I feel about this or that. Don’t ask me my opinions on thing. I mean, they would ask me about women’s issues, and the industry. I had no idea. I didn’t know what to tell them, so I would say something obnoxious. Or try to be funny. It turned into an awkward mess.”

We get up to leave. Ricci has the afternoon off from filming and intends to do laundry. She looks suddenly very small in the street, in her neat vintage coat, pale hands by her sides. “It’s not dark,” she said of the new series. “It’s not serious. It’s light and fun.” She says a polite thank you and, straight-backed and anxious, disappears down the street .

• Pan Am starts at 9pm on BBC2 on Wednesday 16 November.