The Social Network (12A)

The failure who finds how to click

David Fincher's fast-paced business drama adopts the set-up of his 1999 film Fight Club and inverts it. A young man with no particular charm or social skills desperately wants to belong. In Fight Club the protagonist joins a movement that insists on privacy: their first rule is that "you don't talk about Fight Club". In The Social Network the protagonist starts up his own movement, but instead of keeping mum he turns privacy inside out and, terrifyingly, takes millions of people with him.

This fictionalised account of the making of Facebook, smartly written by Aaron Sorkin, hasn't any of the violence associated with Fincher's other work (Se7en, Zodiac et al) but it is nevertheless chilling about the darkness within the male psyche: prepare yourself for jealousy, hatred, deviousness, revenge, and, centrally, flint-hearted betrayal. The film's main character, founder of Facebook Mark Zuckerberg, is prey to all the above tendencies; what's really unnerving about him is that he never shows it on his face. As played, superbly, by Jesse Eisenberg, this 19-year-old Harvard student is an unreadable blank. He twitches and fidgets like a kid, but his intensity is entirely sealed within, like heat in a thermos flask. That he doesn't know how to "be" with people becomes apparent to his girlfriend Erica (Rooney Mara) in the opening scene – set in 2003 – his rat-a-tat-tat monologues patronising, insulting and finally alienating her as he rails against his exclusion from Harvard's elite social clubs. Her exit line to him is damning, and possibly clairvoyant: "You'll go through life thinking girls dislike you cos you're a nerd. But it's not true. They'll dislike you cos you're an asshole". Ouch.

Mark, smarting from this, races back to his dorm and writes a mean blog about his now ex-girlfriend. He also invents a computer program that lets users vote on the hottest women by hacking into Harvard's photo database. This cruel public prank becomes Mark's light-bulb moment. What if he could put people's entire social experience online? He enlists his room-mate and best (only?) friend Eduardo Saverin (Andrew Garfield) to help design it – talk of "algorithms" whizzes through the air – and suddenly something called "thefacebook.com" is up and running. Eduardo, a kinder, less abrasive fellow with social connections Mark seems to envy, stumps up the initial money, too, a commitment that will be contended in a boardroom deposition years later, with the two friends-turned-enemies now flanked by their lawyers.

This bitter legal dispute, which frames the story, is also joined by highborn jock twins Tyler and Cameron Winklevoss (both played, in a sly stroke of digimation, by Armie Hammer), who invited Mark to help them set up their own networking site, Harvard Connection, and were mightily aggrieved once they learnt that the undistinguished nerd had left them for dead. Switching angles and viewpoints, the film teasingly asks us to decide the big one: whose invention was Facebook?

It's an irony that Sorkin's script doesn't have to underline that the pioneer of social networking was – is – about as socially inept as you could get without actually being named Forrest Gump. "He hasn't three friends to rub together", someone says of Mark, and yet he is prodigious in discerning the patterns of disclosure that would entice users into an all-encompassing web of communication. Always distracted, he never seems to say "thank you" or "sorry" to anyone, and during one deposition, when a lawyer pointedly asks him if he has his "full attention", Mark replies, with breathtaking rudeness: "You have part of my attention. A minimal amount." The one person he does pay full attention to is dotcom entrepreneur and Napster founder Sean Parker, played with ruthless suavity by Justin Timberlake. Parker intuits Mark's drive, and knows how a brilliant idea like Facebook should be marketed – invaluable nous that poor Eduardo doesn't have, and will end up paying for.

Shot in glassed offices or shadowy, oak-panelled rooms – Harvard looks more like the setting of a horror movie, which is perhaps what this is – The Social Network clicks along with terrific verve, skating over the geek-speak when necessary to get to the heart of the matter. And that is? I suppose it's social access, with all the rewards that attend it: sex, money, status, drugs. The mystery of Mark is that he doesn't seem to crave any of those things. He's the outsider who wanted in, and yet once he's cracked it he never displays any sense of joy or satisfaction; he doesn't even go to the party to celebrate Facebook's millionth user. Maybe what excites him is the game itself, the working through of a scheme and its dazzling application. Either that, or the fact that he's now the youngest billionaire in the world.

The film is an absorbing and persuasive dramatisation of what might have happened during a frenetic period of recent media history, but I must confess it's not the film I thought, or rather hoped, it would be. At their first meeting, Sean Parker tells Mark and Eduardo that "private behaviour is a relic of time gone by", which issue seems to me far more intriguing than the claims and counter-claims over the authorship of Facebook. The erosion of privacy is a hugely disturbing phenomenon for which social networking sites continue to be a conspicuous facilitator. Facebook now has half a billion users worldwide, but who wants a world of "friends" where actual friendship plays no part? Do the consequences of this not strike the film-makers as dramatically sinister?