Nicholas Hoult on 'Kill Your Friends', Jennifer Lawrence, and being a child actor

​Nicholas Hoult found fame as a child with a pudding-bowl haircut. Now he's playing a grizzled psychopath but he still has plenty to learn, he tells Chris Sullivan

Growing up fast: Nicholas Hoult as Steven Stelfox in 'Kill Your Friends'

It's hard to believe that the tall, well-dressed young man sitting in front of me is the same Nicholas Caradoc Hoult I met when he was aged 12, with a Baldrick haircut, on the set of About a Boy. It's just as difficult to grasp that this extremely well-mannered young man is also the same chap who delivers a sterling performance as Steven Stelfox, the unremittingly sexist, racist, cynical Nineties record company executive in Kill Your Friends, Owen Harris's hysterically funny adaptation of John Niven's best-selling book.

I wasn't at all sure that the 25-year-old Hoult, or for that matter any actor younger than 30, could carry off Stelfox, a complex character, at once noxious and strangely charismatic, who harbours a peculiarly vicious cynicism that usually comes with age.

With Hugh Grant in 'About A Boy' (Rex)

“I wouldn't say it was easy,” chuckles Hoult. “Most characters like Stelfox have some comeuppance or some repentance but he is willing to go darker than anyone else, is extremely twisted, unrelenting and unremorseful right to the very end. Luckily, John Niven's dialogue is hilariously wicked and very, very credible, so it was great to unleash and relish the unmentionable.”

It's not just a triumph of dialogue. Hoult renders the character's ethical descent with body language, while his moral decrepitude is etched deeper and deeper into his eyes as the film progresses. “He starts out very self-controlled,” he explains. “Always sharp and focused, so when he starts to lose control and thinks he is going to lose his job and become everything he despises, panic and fear set in and he decides to do 'anything' to fix this.”

“Anything” includes bribery, coercion, premeditated murder and the merciless framing of anyone who dares get in his way.

“Stelfox epitomises this culture we have that is governed by pure and ruthless ambition over good taste and talent,” says Niven, a former A&R man at London Records for 10 years. “The book became a repository for every gleefully sordid, vicious, corrupt thing I saw.”

Accordingly, one of the film's many hilarious strands sees Stelfox audition a girl band comprising four badly dressed, outrageously talentless floozies. He hates them almost as much as he despises his record business colleagues, so contemptuously finds them a tacky song, overdubs their voices and somehow gets them to the top of the charts. It's all achingly familiar.

“Maybe I'm a romantic,” sighs Hoult, “but I like to look back to the old days when people learned their craft. Now people think they have a right to be famous or a celebrity without doing any work! Some people can act without prior experience – they just get it – but I have to put the time in and still feel I could have done better.”

No one could blame the Wokingham-born actor for not putting the hours in. He made his debut in the film Intimate Relations, aged seven, came to prominence in About a Boy, excelled in Kidulthood, became a heart-throb after a lead role in Skins and hit pay dirt playing opposite Colin Firth in A Single Man.

With Jennifer Lawrence in 'X-Men: First Class' (Rex)

Does he think he missed out on a proper childhood? “Well it's impossible to say,” he replies. “But I feel that I am really very, very lucky. Occasionally I sit back and realise that I've travelled to places where most people have never been and met inspiring, exceptional people that I can learn from. And it was different for me than it is for some American child actors who are taken out of school and live in this weird vacuum that is another world. I stayed in school and would go back to being a normal kid after work, which is invaluable.”

After A Single Man, Hoult's career skyrocketed. He played Hank McCoy/Beast in director Matthew Vaughn's box-office smash, X-Men First Class, was the eponymous lead opposite Ewan McGregor and Stanley Tucci in Jack the Giant Slayer. He then reprised his Hank McCoy role in X-Men: Days of Future Past and embarked on a much-publicised, three-year on-and-off relationship with his co-star, Oscar-winner and the highest paid actress in the world, Jennifer Lawrence.

Rumours abound regarding the pair. Some say Hoult is trying to win back her affections after her affair with Coldplay's Chris Martin as the pair were spotted together as they arrived in Montreal, Canada to shoot X-Men: Apocalypse. An enquiry as to their romantic situation elicits a self-conscious and hugely awkward silence. Dating must have been paparazzi hell, though? “At the time there were moments of that in Los Angeles,” he admits, obviously reluctant to talk. “But I live in London and can get on the Tube and no one will blink an eye. I'm very fortunate like that but I know people whose life has become completely uncontrollable and unbearable.”

Hoult insists he will not lose touch with reality. “I can still go to a pub and have a pint and meander around,” he clarifies. “And I really need that. Once you lose that, it can be very difficult to interpret things in a natural, human way as you're not really part of a natural, human world any more.

“But some of the coolest moments of my job are when someone comes up to you and says, 'I really enjoyed you in that film' – no picture, no autograph – just a genuine moment. That's a great thing. The only thing that bugs me is when people pretend that they're not taking a photo of you. It's like, 'Mate, just ask for a photo – that's completely cool but I can see exactly what you're doing'. What's worse is when you think someone is taking a photo of you so you confront them and they're not. A very well-known friend of mine approached this guy with a big, proper camera who was snapping away in a coffee shop we were in. He walked up and said, 'Dude, like, what are you doing?' But this guy didn't know who he was and, for some reason, was actually taking close-ups of the coffee machine.”

I fear that Hoult's halcyon days of anonymity might soon be behind him. Previous major roles have seen him painted blue and covered in blue fur in X-Men and with his head shaved and skin whitened as the terminally ill nutbag slave on a mission, Nux in Mad Max: Fury Road. But forthcoming releases such as Equals (in which he stars with Kristen Stewart), Rebel in the Rye, where he plays J D Salinger, and Collide, a drug-smuggling film with Anthony Hopkins and Felicity Jones, will surely expose him to the world. Entirely unperturbed, he seems more intent on building up a serious canon of work than worrying about the rigours of fame.

“All I want to do is not repeat myself or take easy film choices,” beams the actor who, of late, has played a soldier, a zombie, a psychotic and a mutant. “I could get offered a period drama, which could be an easy success and financially rewarding, but there are no teeth to them; and at some point you've got to, as Tom Hardy says, earn your pipe and slippers. So yeah, I've got a lot to prove and a lot of things to learn, and a lot of room to get better.”

'Kill Your Friends' opens on 6 November