Early on in the film, The Social Network, Facebook creator Mark Zuckerberg goes to a party organised by Harvard's Jewish fraternity, Alpha Epsilon Pi. It is a Caribbean-themed bash, complete with half-hearted tropical decorations and students mingling with colourful cups of punch in their hands. One or two make a desultory effort to dance.
It is fairly obvious that this is not a "cool" party. But even in this unmistakably nerdy environment, Zuckerberg does not feel at home - he is outside, pacing around, deep in the thrill of his new computer project.
That project became The Facebook and eventually just Facebook, arguably the most influential website on the planet, with 500 million members and an estimated annual revenue of more than $2 billion. Zuckerberg, now 26, was listed in the latest edition of the business magazine, Forbes, as the 35th richest person in America, with a fortune of $6.9 billion.
For its teenaged mastermind, Facebook was a place where the ultimate interloper could become an insider, part of an exclusive group. It was a place where the self-described "awkward" Jewish boy from suburban New York could reinvent himself as a creative genius, mixing with Silicon Valley legends and glamorous women.
At least, that is how Ben Mezrich sees it. The author of The Accidental Billionaires, on which The Social Network is based, says being an outsider was a big part of what led Zuckerberg and his original business partner, a Brazilian Jew called Eduardo Saverin, to set up Facebook.
"Mark and his friends were geeky, brilliant kids who had their faces pressed up against the glass," explains Mezrich. "On the other side was the social scene they weren't really a part of, and they created their own club, an exclusive, incredibly social place where they could be kings."
Hailing from a conservative Jewish family - his grandfather was a rabbi - Mezrich knows something about not fitting in at a prestigious university. Like Zuckerberg and Saverin, he attended Harvard, where he was a self-confessed "geeky kid", and acknowledges that as a Jewish boy from Brooklyn who had not come from "a long line of people who had gone to Harvard", there were opportunities that were not open to him.
"There are these groups where there is this old world aristocracy going on," he says. "People like me - and Mark - couldn't really be a part of that."
The Harvard of Mezrich's book, brought to cinematic life by West Wing writer Aaron Sorkin and director David Fincher, reeks of Ivy League exclusivity. The badge of honour is membership of one of the eight elite "final clubs", all-male, WASP societies which have, explains Mezrich, "nurtured generations of world leaders, financial giants, and power brokers".
Membership "granted an instant social identity," says the author. Neither Zuckerberg nor Saverin came from deprived backgrounds, but they still were not final club material.
In Mezrich's retelling of the genesis of Facebook, Saverin's preoccupation with climbing the social ladder helped drive the pair apart, prompting Zuckerberg to cut him out of the business by heavily diluting his shares, sparking a lawsuit from Saverin.
How accurate the book and subsequent film script are has been the subject of much debate. Mezrich admits to recreating dialogue and reworking the chronology of events to neaten the narrative. The book is almost wholly based on interviews with Saverin, who having gone from Facebook chief financial officer to persona non grata, could be accused of having an axe to grind. Zuckerberg, says the author, "simply wouldn't talk".
Unsurpringsly Mezrich defends his work. "I felt strongly that the book was a very fair representation of what happened," he says. "Eduardo is the one who came to me, but I also spoke to everyone else except for Mark."
Zuckerberg, who is notoriously publicity-shy, has described the film as "fiction" and criticised it for portraying him as "someone who built Facebook so I could meet girls".
But Mezrich is keen to stress that the Zuckerberg everyone knew at Harvard was an outsider, "a socially awkward kid who wanted to create a social network he could be part of".
Whatever the reality of the situation, as the creator of a new social world with its own language and etiquette, Zuckerberg is now not just part of a network, but at its very heart.
What the users say
● Elliott Cantor, aged 23, promotions manager, from Cardiff, 3,604 friends
"It is somewhere people who feel like 'outsiders' can come and make new friends they wouldn't have found otherwise. And it can be quite Jewish because it lets you see who your mutual friends are, and the question whenever you meet new Jewish people is 'do you know…?' Now, to save asking this, you can see who you both know from mutual friends on Facebook."
● Anthony Goodmaker, 23, law student, Stanmore, 760 friends
"Facebook is the ultimate proof of how small the Jewish world is and a great way of snooping and seeing who knows who. Also, looking through peoples photos you will always spot friends of friends, so I'd say Facebook facilitates the Jewish way of life and helps maintain the closeness of the com-munity."
● Sabrina Geva, 21, Israeli graduate living in Ham-burg and London, 445 friends
"Jewish people like to gossip and Facebook offers this. You can tell by a person's 'friends list' who they socialise with and thus what type of person they are. You can judge a person by the friends group that he or she belongs to - it is very sad but true."
● Richard Daniels, 22 medical student, Pinner, 992 friends
"The homepage idea of not just seeing your own interactions with others, but seeing your friends' interactions with each other could only have been invented by a Jew. It's the ultimate passive gossiping tool - you don't even have to let everyone know you're nosey!"
● Colin Myer, 25, PR, Barnet, 550 friends
"What's strange about Facebook is you realise there are people you have 60 or 70 mutual friends with but have never met them or even realised they exist.
"Facebook makes the Jewish game of 'do you know this person then?' much less exciting as it plays it with the unerring and boring success of a machine and with a database containing far more information than the human mind can hold."