"Oh, how lovely," she says. When I gush my apologies for being so unoriginal, she concedes that she does hear this a lot, but adds that, "It never gets old. Never." It must be odd, though, to have people from around the world wanting to talk about a book you wrote 20 years ago. Did she have any idea while she was writing it that it would resonate the way that it did? "I had an instinct or intuition that it would," she says. "All the young women I knew were grappling with these issues very profoundly. I think there are some ideas that are part of the collective consciousness. One person or three people might be the first to put it together, but the energy was out there anyway." There's a similar "energy out there" right now, if the spate of books, articles, grassroots campaigns and political rhetoric about the relationship between the media, body image and sexualisation of girls is any indication. Which is not to say that the issues today are exactly the same; indeed, rereading the book in 2010, it's fascinating to note how much has changed - for better and worse. For starters, much of what was revelatory to me back in the day would be eye-rollingly obvious to today's media-savvy teenagers. This is, Wolf agrees, a very good thing. "When I wrote The Beauty Myth, it was considered almost taboo to question the ideal. The assumption was that there must be something wrong with you: you don't measure up, you're a dissatisfied shrew. But now it's normative. We have girl scouts learning to question the ideal of beauty and Hollywood stars giving interviews about loving your body."

Yet despite the cultural shift, the beauty industry has continued to grow. Understanding that the images they see are manipulated by technology and that the messages they hear are designed to make them buy stuff hasn't lessened women's desire to conform to those images. Meanwhile, you only need to glance at the spread of glossy magazines in your local newsagent - with every cover model an airbrushed echo of the woman who originally posed for the picture - to see that the beauty ideal has become narrower. "It's a whole new mutation," says Wolf. "When I wrote the book, fashion models were the thing, but now fashion models don't seem to be that important in terms of the beauty myth. It's more starlets and Hollywood." Wolf attributes the change to "the democratisation of the luxury industry ... The luxury brands began to see a giant market in ordinary people, young girls especially, so they joined forces with Hollywood and made brand-placement deals with these ingenues. I think that as a consequence these starlets have had to turn up the volume, get smaller and smaller, get more and more surgery, because they're part of the brand and they need to lure new people." Nevertheless, Wolf, who has a teenage daughter and a pre-teen son, is relatively relaxed about how the millennial generation is dealing with the beauty myth. "I don't worry about the young women of today the way I used to with young women of the '80s and '90s because I think they're doing it from a different place. While they do pay attention to how they present themselves, they're not torturing themselves, not feeling worthless or thinking, 'If the scale goes up a pound I'm a bad person.' "I think even in a total feminist utopia, teenage girls are going to go through some amount of anxiety or self-inflicted discomfort or obsessiveness about self-presentation because that's just part of the transition. I think as long as they're still feeling good about themselves in general and having adventures and holding their own with young men and not letting themselves get pushed around ... I don't worry about them so much." Which is not to say everything is peachy. Wolf acknowledges that anorexia and bulimia remain problems and says she still meets some girls who are "tortured" by body issues. "The other thing that's gotten worse is that the technologies for cosmetic surgery have multiplied and also the expectations have multiplied." Indeed, according to the American Society for Aesthetic Plastic Surgery, there has been a 147 per cent increase in the number of cosmetic procedures performed in the US since 1997. Ninety-one per cent of these were performed on women and 20 per cent on people under 35. (National statistics are not collected in Australia, but anecdotally, cosmetic surgery is increasingly common.)

Overall, though, Wolf thinks that "women of my generation and the one under can pat ourselves on the back that all this angst we directed at changing things for young women has actually borne fruit." Something that has got "much worse", according to Wolf, is the influence of pornography, which "has become the air that we breathe ... it's definitely affecting young women and men's sexual development deeply, deeply, deeply." Pornography has long been a contentious subject for feminists, although it's not, as stereotypes would have it, a case of anti-porn feminists screaming for censorship on one side and raunch feminists mindlessly swinging their nipple tassels on the other. In the past decade or so - a period in which we've seen the proliferation of free, easily accessible internet porn - feminist debate around pornography has been focused on the effects it might have, positive or negative, on the women in porn, the women who watch it and the women in relationships with men who watch it. So when Wolf wrote an essay in New York magazine in 2003, centred on the effect of porn on young men's sex drives, there was quite a stir. "The onslaught of porn," she wrote, "is responsible for deadening male libido in relation to real women ... Far from having to fend off porn-crazed young men, young women are worrying that as mere flesh and blood, they can scarcely get, let alone hold, their attention." Critics ridiculed the idea that young men were turning down sex with willing, flesh-and-blood women, and although I believe Wolf when she tells me that "many, many men" have written to her since saying, "Yes, it's true", I remain unconvinced that this is a generation-wide phenomenon. Nevertheless, returning to the article seven years later, I'm forced to admit that when it comes to the effect of ubiquitous pornography on the sexual self-confidence of young women, she has a point. When I first read Wolf's claim that hers was "the last female generation to experience that sense of sexual confidence and security in what we had to offer", I scoffed. Now, I tell her I hope she's wrong, but am increasingly worried that she's not.

In the past few years I've spent a lot of time talking to women in their teens and early 20s about porn, sex and body image. There is a profound difference in the context in which these women have come of sexual age compared to that of my adolescence only a decade earlier. The difference is that most young people now have witnessed countless sex acts long before they even get naked with another human being. It could be argued that such exposure is educational, but only if you've never seen any mainstream porn, which is, most industry insiders and observers agree, getting more and more extreme. This may be, at least in part, a reaction to the adoption of soft-porn aesthetics by mainstream popular culture. Porn needs to be nastier and more hard-core to differentiate itself from beer ads and music videos. Anal sex, for example, is now a standard part of heterosexual porn, and although this is not necessarily a brutal act, the way it's performed in these films usually is. A bit of spit on the woman's orifice is all the preparation and care the men take. On visits to college campuses, Wolf learnt from health educators and counsellors that women are coming in with anal fissures caused by sex. "I'm not making a [moral] judgement about it," Wolf says. "But it's an intense act and on a first date, or on a hook-up on a Saturday night with someone they don't know, girls feel like they have to provide anal sex. This doesn't seem like the kind of thing they'd be doing if they felt, 'I'm 100 per cent fabulous, I'm setting the pace, taking my time.' It seems like the kind of thing girls do when they're trying to live up to one ideal or another." The other big trend in mainstream porn is to end a scene with a man ejaculating on a woman's face. Again, there's nothing wrong with the act in itself, but there's something disturbing about the way it has become the norm within what has become a widely watched and imitated form of media. This is especially worrying when you realise that the context in which it's presented is often one of deliberate humiliation. The idea seems to be that no matter how hot and confident the woman is at the outset, by the end she'll be a sticky mess, with smudged make-up, watery eyes and no hope of getting satisfaction herself now that her partner has finished with her.

Sexually experienced adults may understand that what they're watching is a fantasy, carefully choreographed, performed by professionals and shot for maximum visual impact rather than physical pleasure. But many teenagers don't know this; hence the horror stories of first-time sex that begins with rough, sudden penetration and finishes with semen in the eye. To be clear, the concerns Wolf is raising are not about the morality or otherwise of watching porn or having sex of whatever kind; they're about the effect that early, repeated exposure to pornography is having on young people's sexuality. "Young women do compare themselves to pornography and they do have porn running in their heads when they're in sexual situations. I'm not a prude, but I don't think that's good for their sexual confidence or confidence in their bodies." Indeed, young women I speak to often express anxiety about the appearance of their genitals, which seem to them so much "messier" than those they see in high-definition close-up on the screen. Although no statistics are collected in Australia, surgeons specialising in labiaplasty (basically a nip and tuck of the labia) claim it's a growing field. One Australian surgeon recently told a cosmetic surgery conference that he used to see only "the professionals - the pole dancers, the strippers" but now he was seeing a lot of "young girls who are concerned that their partners in sex may in fact be put off by the appearance of their vulvas". Contributing to the problem is the fact that it's illegal in Australia to publish images of vulvas that show anything more than "a single crease". This means that even women's magazines aren't allowed to show real, un-pornified, un-photoshopped female genitals for educational purposes. I'm reminded of something Wolf wrote in The Beauty Myth: "We are asked to believe our culture promotes the display of female sexuality. It actually shows almost none. It censors representations of women's bodies, so that only the official versions are visible." This in turn brings to mind the argument that certain kinds of pornography are liberating because they do show human bodies and sexualities in their uncensored, infinitely variable glory. What of the young gay, lesbian and transgender people who say pornography is empowering to them because it celebrates their sexualities when other forms of media shun or ignore them?

What of the young women who say that non-mainstream pornography helps them to accept their bodies and become more confident in their sexuality? Can pornography be a positive force? "Oh, you're wading into a thicket," Wolf says. "You're right to, but ... it's so complicated. I know that seeing a sexuality that's been kept hidden or criminalised can be liberating for gay and lesbian people, certainly. I'm also really interested in sex; it fascinates me and I'm not going to say there aren't erotic images or works of art or works of theatre or paintings or photographs that don't appeal to me." She pauses. "I guess I go back to that's why I don't think feminism will ever triumph if it's saying, 'Okay, this kind of erotic image is legitimate because the people look like Smith [a private liberal arts college] graduates or are overweight and this is not okay because it's made by a big studio.' That's hair-splitting and I think we need [to resist the] reflex to label something good or bad. Thinking for yourself is a lot more liberating. I'm always going to return to asking a person how does it make them feel. What's the lasting effect on their love life, their sex life? Research shows that pornography desensitises; if you consume it a lot, you need more or more extreme or more and more intense images in order to get the same sensations over time ... If you care about your sexual response - you want to protect it, keep it fresh - you might want to not look at pornography for that reason. "The question is not whether it's acceptable or unacceptable, but what issues does it raise for me or you and let's make choices about what we want to consume. I know that's not as satisfying as a firm declaration that A is good or B is bad." Wolf, "a free-speech absolutist", does not advocate censorship. In any case, she says, attempts to ban pornography wouldn't work. "It's like the military-industrial complex: so much money's being made that there's no way to stop it at the source. The best thing we can do is try to persuade young women and men that it's not good for their sex lives, it's not good for their self-confidence, and they'll have better sex if they choose not to let this stuff shape their sense of sexuality." Of course, that's an argument to be made to adults who consensually consume porn. On the current Australian debate over the display of porn magazines in service stations and supermarkets, Wolf is unequivocal. "I think it's appropriate to keep pornography away from children. I don't think it's censorship to keep public space porn-free - people still have a choice about when they want to consume it. I don't feel it's right to impose pornography on people in the public sphere."

As fascinating as it is to observe how things have shifted in the past 20 years, it's hard not to feel dispirited. After all, porn-inspired body hatred is no better than the Vogue-inspired kind. "If you look at ideologies directed at women, they migrate," Wolf points out. "Like, once women figure out, 'Oh, I'm being manipulated by the ideology of housework,' it will migrate to beauty obsession. Once they figure that out, it migrates to, 'Oh, your genitals are ugly.' I don't think it's a conscious conspiracy - it's something that the culture tends to do." The good news is that we need not be victims of that culture. The Beauty Myth taught masses of women to question harmful media images and messages. The challenge now is to do the same for a new generation facing a new onslaught. And as we do so, we'd do well to remember that, as Wolf wrote in 1990, "Sexual explicitness is not the issue." In fact, "We could use a lot more of that, if explicit meant honest and revealing." " On the eve of the 20th anniversary of The Beauty Myth, Naomi Wolf revisits her landmark book at the Capitol Theatre, Melbourne, this Thursday at 7.30pm. Bookings through wheelercentre.com.