When I was at college 20-odd years ago, there was a ‘computer room’ where you could go if you ever felt the urge to type something. Almost nobody used it. Except for a few awkward young men in stripy Christmas jumpers, known as ‘geeks’, who practically lived there.

Those geeks have since inherited the earth. Information technology is now the world’s most fashionable profession, which is why the new film jOBS, with Ashton Kutcher as Steve Jobs, closes the Sundance Film Festival. Aaron Sorkin is also working on a biopic of Jobs, having previously written The Social Network about Facebook’s Mark Zuckerberg.

Hollywood, as the most commercial art form, provides our best measure of the zeitgeist. One thing its movies do is nudge middle-class young people without a particular vocation into certain professions. Currently, that profession is IT. But as journalists and bankers can testify, this supremacy won’t last. The Darwinian struggle between professions never ends.

Athletes, singers, cops and robbers are always fashionable, but society also needs white-collar role models for youngsters, even now when they can’t get into any profession at all. In mass media’s heyday, journalism ruled. Tintin and Superman were reporters; Citizen Kane was a newspaper magnate. Fellini’s La Dolce Vita (1960) glamorises the spread of tabloid journalism in Italy, with a photographer named Paparazzo, and Marcello Mastroianni playing the journalist as romantic hero. By my youth, the spotlight had shifted to worthier journalism.

All The President’s Men, The Year of Living Dangerously, The Killing Fields and Salvador all appeared between 1976 and 1986.

Then banking took over. Films such as Wall Street (1987), Working Girl (1988), as well as bestselling books such as Tom Wolfe’s Bonfire of the Vanities and Michael Lewis’s Liar’s Poker, didn’t portray bankers as good guys. But they did portray them as ‘masters of the universe’ who didn’t eat lunch.

In my college days, most students who didn’t know what they wanted to be wanted to become bankers. The early-1990s recession checked that.

I remember a college friend, who had duly joined a merchant bank, telling me glumly that the new movie Presumed Innocent (1990) starred Harrison Ford as a lawyer. “Last year,” my friend lamented, “that character would have been a banker.” Soon Tom Cruise was playing lawyers too. Lawyers - usually public-interest or criminal rather than corporate lawyers - are Hollywood’s perennial fallback when no other profession seems sufficiently fashionable.

Some professions will never be fashionable. The Secret Lives of Dentists (2003) is meant to be a ridiculous title, but bottom of Hollywood’s heap are accountants. Here is Jack Lemmon’s character in The Apartment (1960) introducing himself: “I work on the 19th floor. Ordinary Policy Department, Premium Accounting Division, Section W, desk number 861.” The mix of accounting with insurance is intended to sound particularly hilarious.

Now journalism is becoming equally unglamorous. The death-knell was George Clooney’s Good Night, and Good Luck (2005), set in the US in the 1950s. Once they start making historical movies about you, you might as well be a knight or a boxer: you’re finished.

Today Hollywood uses journalism as an amusing side-job for female leads in romantic comedies — women whose real business is finding love. Alternatively, journalism gets parodied.

Since 2008, banker types generally get portrayed as sad, fading villains: Michael Douglas in Wall Street 2, Richard Gere as a hedge funder in Arbitrage.

Hollywood increasingly draws on the food-and-beverage industries (Sideways, Julie & Julia, Ratatouille), but nothing now matches IT’s allure. The computing industry specialises in the timeless Hollywood script of kid overthrowing old order. Moneyball (2011), in which mathematicians with laptops upend baseball, retells the Triumph of the Geeks story.

But it won’t last. Ominously for IT, this year’s Hollywood hero, Jobs, is dead. Before long they’ll be making historical movies about Silicon Valley.

I wish I could predict the next fashionable profession but, given my own choice of career, I’m the last person to ask.

— Financial Times