The first season of Lena Dunham’s Girls must be the most argued-about five hours of American scripted television in recent memory. With the comedy impresario Judd Apatow (Knocked Up, Bridesmaids) as executive producer, the series – about four women in their twenties living in New York – at first generated radiant reviews and profiles. From these sprang dozens of online opinion pieces and blog posts that in turn sprouted seemingly endless, contentious comment threads.

Among the squabbled-over points are whether the show realistically represents the lives of young women today; whether it suggests that the sex lives of said young women are pitiably unfulfilling; whether it heralds a new flourishing of mainstream culture that reflects the concerns of young women. Its fiercest critics have faulted the series for the following reasons: the characters are too privileged; the creators (Dunham, daughter of two New York based visual artists, and a cast that includes the daughters of the playwright David Mamet, the news anchor Brian Williams and the rock
musician Simon Kirke) are too privileged; the 26-year-old Dunham (who stars as well as writing and directing) is too young; Dunham is insufficiently attractive; the characters are too white; the characters are too unlikeable. Defenders of the show have accused the critics of envy, short-sightedness, obtuseness and assorted prejudices, not least of which is sexism.

Girls will arrive in the UK trailing clouds of these debates. This sort of show can’t be meaningfully separated from the highly digitised conversation about it. The online rumination over what it all means even goes on within the series. The main character, Hannah Horvath (Dunham), can be seen at the end of the third episode glumly hunched at her laptop in the dingy Brooklyn apartment she shares with her best friend, Marnie (Allison Williams), contemplating what to tweet. Will it be a cryptic allusion to a day of crappy revelations? She’s learned that she has genital warts and her ex-boyfriend, who has just come out of the closet, informs her that her current boyfriend is probably lying about not giving them to her. Or should she make a more straightforward reference to her woes? Instead Hannah opts for a phrase that serves as the episode’s title: “All adventurous women do.” It’s the sort of “yougo- girl” affirmation that might have summed up a Carrie Bradshaw column and with it a Sex and the City episode, read in voice-over by Sarah Jessica Parker. Television shows such as these float new ways of interpreting contemporary life and manners. They were designed to be talked about.

Still, that doesn’t mean that all the ambient chatter hasn’t polluted many a viewer’s response to Girls, whether they’re primed to welcome it as a revelation or they have their knees cocked for a rejecting jerk. In the opening episode, Dunham has Hannah, an aspiring writer, say: “I may be the voice of my generation. Or at least a voice of a generation.” She’s asking for trouble and she knows it – hence the equivocation. For every viewer who claims to see herself in Hannah or one of her friends, there’s another who takes exception to the idea that she could, like Hannah, afford to take an unpaid internship for two years. If you even gesture toward speaking for a generation, then anyone in that generation becomes instantly invested with the authority to say you’ve failed.

It isn’t possible to depict every twenty something New Yorker’s experience in a half hour comedy series but you can’t blame Dunham’s detractors for their annoyance. The young are particularly vulnerable to being saddled with generational voices; no one expects television characters in their thirties or forties to represent everyone in their age group, after all. At the same time, people in their early twenties are consciously trying on new identities. Malleable and protean, twenty-somethings often look to culture and the media for cues. Marnie claims that the musical Rent is “basically why I moved to New York” and Shoshanna (Zosia Mamet) describes herself and everyone she knows as an amalgamation of the four central characters in Sex and the City.

The Sex and the City legacy doesn’t extend as far as you might guess, even though both series were produced by HBO. The bonds between Hannah, Marnie, Shoshanna and her British cousin Jessa (Jemima Kirke) may be the core subject of Girls but nobody is likely to covet this foursome’s lifestyle, copy their outfits or, when visiting Manhattan, make a pilgrimage to their favourite cupcake shop. Girls isn’t aspirational. Not, that is, unless you aspire to average wardrobes, exploitative starter jobs, cramped and grubby apartments, exasperated parents and marginally employed boyfriends.

Authenticity, not glamour, is the calling card of Girls and that authenticity is personified in its creator. The preternaturally talented Dunham has exquisite comic timing combined with a deceptively natural delivery but what audiences notice first is her body and the way she uses it. She (unlike Williams and Kirke) is not beautiful by conventional Hollywood standards; she’s chubby and, in the wrong light, can look potato-faced. Dunham revels in the wrong light.

In Girls, as in her similarly autobiographical low-budget feature Tiny Furniture (2010), she films herself naked or padding trouserless around her mother’s loft, shoulders slumped and belly pooching out. It’s not just that she’s without vanity – she’s without shame, which registers, at a time when many young women are mortified by not measuring up to starlet standards, as far more transgressive than all the kinky paraphernalia in Stanley Kubrick’s Eyes Wide Shut.

Dunham’s frankness extends to Hannah’s personality flaws, which are plentiful. When, in the first episode, her parents announce that they’re cutting her off, she makes what we will come to recognise as a classic Hannah move, deflecting their complaints with an alarmist, topical digression about the prevalence of prescription drug abuse among “kids”. Her mother, the tougher of the pair, tells her to get a job: “You are so spoiled!” “Well, whose fault is that, mom?” Hannah retorts. After crashing in her parents’ hotel room, she wakes to find them gone and (surely her lowest moment) pilfers the tip they’ve left for the maid.

Hannah has a loyal best friend in the orderly Marnie and a peculiar, strings-free relationship with Adam, a semi-feral actor-cum-woodworker she only sees at his apartment for impromptu booty calls. Their sexual encounters are disorientingly realistic, all anxious negotiations and awkward interjections of “Is this OK?” and “Should I just keep doing this?” Completely unselfconscious, Adam enlists the bemused-but-game Hannah in some hair-raisingly dirty, pornified role playing.  Meanwhile, Marnie waffles over breaking up with her too-sweet long-term boyfriend. Jessa, a seductive, globetrotting trickster, arrives in a cab from the airport to stay with Shoshanna, a naive motormouth.

At first, these characters, though freshly sketched, are simply more knowing versions of the figures who populate most half-hour comedies. Hannah is a young, female Woody Allen, clever but neurotic and self-absorbed. Marnie is, in her own words, “uptight”. Jessa is the intimidatingly worldly man-eater. Sho - shanna is comic relief. Yes, it’s gratifying to see a filmed Brooklyn party scene that actually resembles a real Brooklyn party and, yes, the series excels at nailing previously unclassified social types. There’s the finance guy who talks boringly about his penchant for making hiphop mash-ups and there’s the pretty, opportunistic memoirist cashing in on her boy - friend’s suicide.

However, if this were all there was to Girls, it would ultimately be reducible to what many critics accuse it of being: a hipster iteration of Sex and the City. It’s not. Even the best sitcoms are fundamentally static and presentational; what you see of Jerry Seinfeld or Liz Lemon or Carrie Bradshaw is pretty much what you get. Girls, on the other hand, is full of secrets. As the ten half-hour episodes of its first season unfold, it shows itself to be invested in the gradual excavation and evolution of character.

So give Girls a chance, whatever you’ve read about it in advance. The characters and the events in the first few episodes are not necessarily what they seem. Watch closely. They may surprise you, which is not something representatives of a generation – any generation – typically do. Yet it is something human beings do and human beings are what Girls, in the end, is all about.

Laura Miller is a co-founder of salon.com “Girls” will be broadcast on Sky Atlantic from October.