Mark Zuckerberg, founder and chief executive of Facebook.

It is supposed to be one of the most dynamic companies the world has ever seen. But until recently Facebook was deeply sexist and stuck in a 1950s mentality that was a cross between a frat house and Mad Men, a new book by a former senior staff member claims.

Women working at the social network were propositioned for threesomes or given crude insults like “I want to put my teeth in your a**”, claims Katherine Losse.

Lower-ranking employees, invariably women, were treated like “second-class help”.

Meanwhile, in-between toga parties and late-night “hackathons”, male engineers raced skateboards around desks as if they were in the X Games.

Facebook founder Mark Zuckerberg is compared to Napoleon and branded a “little emperor” who created a company where his staff could “idol-worship” him. On his 22nd birthday, woman workers were asked to wear T-shirts with his face on in his honour.

The claims are in The Boy Kings: A Journey into the Heart of the Social Network by Losse, who worked for Facebook between 2005 and 2010.

She was employee No 51 and worked her way up from customer relations to a senior marketing role before becoming Zuckerberg’s speechwriter.

At its core, she claims, Facebook is all about creating a “popular techno frat that didn’t exist at Stanford or Harvard”, where men can engage in endless competition with one another.

Chosen programmers were treated like “prodigal sons”, while women were just along for the ride.

She writes: “The older men in the office could be as unbridled in their wide-ranging desires for sex and attention as the youngest ones.

“One of the few married engineers on the team was known by his female colleagues (after he had made several unwelcome propositions to them) to invite lower-ranking women at the company to have threesomes with him.

“When a female employee reported being told by a male co-worker in the lunch line that her backside looked tasty – ‘I want to put my teeth in your a**’ – Mark asked (it was hard to tell whether it was with faux or genuine naiveté): ‘What does that even mean?’

“During an away trip to Las Vegas a group of Facebook engineers filmed themselves inviting girls up to their table in a club then shouting ‘Leave, you’re not pretty enough!’ when they didn’t like them.”

The 2007 “F8” conference in San Francisco was open only to technical employees, but Facebook relented on everyone else – so long as they carried out coat-checking duties while there. This meant lower-paid employees, invariably women, were treated like “second-class help”.

The year before Facebook had offered its staff a $1 000 monthly subsidy to live within about 1.6km of the office in the belief that it would make them happier.

But until there was an outcry this was only offered to engineers on $80 000-a-year salaries.

Customer-service workers, which included the few women who worked for the company, were told they could not have it even though they were on just $30 000 a year.

Losse says one young designer told her “Everyone upstairs is dumb”, referring to the floor above engineering – the one she was on.

“The company’s entire human resources architecture was constructed on the reactionary model of an office from the 1950s in which men with so-called masculine qualities (being technical, breaking things, moving fast) were idealised as brilliant and visionary while everyone else (particularly the non-technical employees on the customer support team who were mostly female and sometimes, unlike the white and Asian engineering team, black) were assumed to be duller, incapable of quick and intelligent thought. It was like Mad Men, but real and happening in the current moment, as if in repudiation of 50 years of social progress.

“Facebook, it seemed, wanted to have it all: to be the new and scrappy kid on the block and have the feel of an old boys’ club that had been around forever.” It wasn’t until the arrival of chief operating officer Sheryl Sandberg in 2009 that things changed.

In an interview to promote the book, Losse said: “I think it had made a lot of strides forward. Obviously, Sheryl’s arrival really helped… because when she came in, she said: ‘I really care about this. I want this to be a great place for women to work.’ I think it’s taken some work, but I think it’s getting much better.”

Losse recounts that during her stint at Facebook there were also some good times. But there was the inevitable excess of Sean Parker, the bad-boy founder of Napster who was Facebook’s first president. At the 2007 Coachella music festival, Losse and some other Facebook staff were relaxing at their rented house when Parker showed up with “a doctor’s bag full of drugs, which everyone politely declined”.

Facebook declined to comment. – Daily Mail