Mad Men star Vincent Kartheiser: 'I think people want to punch me in the face'

He’s a slimy, self-pitying womaniser– and that’s how Pete Campbell has become Mad Men’s most interesting character. As the acclaimed period drama returns for a sixth series, just how much of the reprehensibly ruthless ad-man is there in Vincent Kartheiser?The actor reveals all to Gerard Gilbert.

Pete Campbell is not what you'd call a man's man. He's not exactly what you'd call a woman's man either, unless you're the sort of dame who goes for slimy, self-pitying and ruthlessly ambitious creeps with the face of an overgrown choirboy.

Peggy Olson (Elisabeth Moss) was seduced, of course, but then Peggy was so young and innocent when she was first thrown into the Sterling Cooper secretarial pool. And Trudy (Alison Brie) married him, but then poor Trudy doesn't even begin to understand her man. It's maybe what will save their marriage.

But if you're an unreconstructed type of male, the very thought of Pete Campbell's beady smirk might have you clenching your fists in reflexive preparation for giving him a good pasting – just as Beth's husband handed out in the final episode of the fifth season of Mad Men, when he realised Pete had been sleeping with his wife. The scene went viral online, a bloodlust satisfied, it seems.

"People have been waiting for that for years," agrees Vincent Kartheiser, the 33-year-old actor charged with bringing this conflicted 1960s ad-man to life. "I think people definitely want to punch me in the face… I have that effect on people." He does, or Pete does? "In real life? Goodness no – I'm a tiny little man. I have been hit in my life but generally I try to slow the escalation of aggressiveness by shutting my mouth and walking away."

Buttoning his lip – that's not something Pete Campbell manages so easily. He's the perpetually unsatisfied child of chilly Wasp snobs, who hits on female underlings but crawls to his bosses – that's when he's not trying to blackmail Don Draper (Jon Hamm) to get a promotion. And as Draper's story becomes arguably less interesting with each passing series, it's Pete who is emerging as the more fascinating character. He's not without his admirers, including his (and the show's) creator, Matthew Weiner. "I love him," Weiner has said. "He could be Holden Caulfield's roommate, who borrowed his coat and never brought it back."

"There is a hostility towards people who are born with a silver spoon in their mouth," says Kartheiser in defence of his character. "Pete Campbell represents this type of man who believes he should achieve everything without ever having struggled – but I think what people don't understand is that it's just as hard a road to travel. If you don't succeed, then you're an utter failure, and when you do succeed, then people say, 'Well, that's to be expected… you had everything.'"

Poor Pete, and fair enough – but then there's his inexcusable attitude towards women. He practically raped (some have argued that he did, but Kartheiser disagrees) his neighbour's German au pair, he seduced Peggy (with a fantasy about hunting and gutting animals!) and got her pregnant, he pimped out Joan in order to win an account ("Would you call Cleopatra a prostitute?" ), had an affair with a fellow commuter's spouse, and is generally awful to his poor wife – including the memorable moment when he threw her roast chicken out of the window.

"Now there is something I have to point out," interjects Kartheiser. "Relationships between all men and women on this show are like that of Pete Campbell. I mean, what does Pete Campbell do that Don Draper does not? I think people judge Pete Campbell quite harshly. I'm not trying to justify his behaviour, I'm just saying I don't think that's the primary reason for the dislike of Pete."

Last year's episodes left his character in the midst of a full-blown midlife crisis, but the usually tight-lipped Weiner has been quick to scotch rumours that the character might (spoiler alert here, for anyone who has yet to see the fifth series) follow British number-cruncher Lane Pryce, played by Jared Harris, and actually kill himself. "I know the character of Pete very well and I don't see Peter Campbell as someone who would ever commit suicide," he has said.

"I'm happy to know that," says Kartheiser. "But Matthew rarely does what we think he's going to do. Jared Harris… a lot of people were surprised at that. It wasn't that it came out of nowhere, but such a great actor, he was such a loved character."

Kartheiser is busy growing out his hair – when not on duty he wears it long, grows a beard and generally likes to hang out in the sort of grungy clothes that are the antithesis of Mad Men style, although he has admitted that the show has turned him into more of a "suit guy". "To put on a suit is a celebration," he told reporters at the launch of the Brooks Brothers limited-edition Mad Men suit (yours for just $998). "It says there's something fantastic going on."

Kartheiser first came to Hollywood as a callow 14-year-old. The youngest of six children in an artistic Minneapolis family (his father was a tool-maker, but his four sisters and one brother are all highly capable musicians), Vincent was the spoiled one. "I had this amazing way of getting my sisters to do things for me," he says – the prototypical Pete Campbell, you could argue. "I could just lie on the couch and get my sisters to do my bidding."

Having become a fixture on Minneapolis's children's theatre and voiceover scene, he arrived in LA while still a high-school freshman to try his luck with the 1993 pilot season (winning his first screen role, a bit part in the Christian Slater movie Untamed Heart), and decided to stay on. "I loved it because when you're 14 all you want to feel like is an adult," he says. "I had my own place to live, I had a girlfriend, there was no school, most of my friends were adult… I could do all the bad things that teenagers want to do with my parents being very far away. It's very difficult to discipline your kids from across the country. I went off the rails a bit."

Not so much that in the meantime he wasn't amassing increasingly prominent juvenile roles, culminating with the starring part – as a computer hacker – opposite Patrick Stewart in the 1997 action comedy Masterminds. His first role in an adult film came with Larry Clark's Another Day in Paradise, playing a homeless drug addict. It was k a role that included explicit sex scenes with co-star Natasha Gregson. "I switched [to films for adults] when I was 18," he says. "Kids do it all the time now, but back then it was really difficult… child actors did not have successful adult careers."

This was followed by the Dostoyevsky update, Crime and Punishment in Suburbia, and then a retrograde move, playing a teenager again – a moody adolescent vampire in Joss Whedon's Buffy spin-off Angel. "It felt like a backward step," he says. "I was worried that this was all I could book, but it did get me working hard again, and I got serious about acting again. I realised what I had been doing in my twenties was a very complacent type of acting – when you're a kid actor all that is required of you is to be real. As an adult you have to bring something to the part."

Kartheiser took to the stage, and chose smaller, more interesting roles in films so that he could take more risks. "With these small roles I started to get confident," he says. "When Mad Men came along I was ready. I had a real idea of what I wanted to do with it and I'm glad Matt [Weiner] liked it because I don't know what I'd be doing if it hadn't been for Matt."

Now, after six years and five seasons, there is a feeling that Pete and his opposite coin Peggy (the newly liberated, increasingly self-confident working woman) are the future, not the dinosaur alpha-male Don Draper. That said, there's still no doubt that Jon Hamm is the star, if not the least bit starry. "I've never heard Jon complain," says Kartheiser. "He never takes a day off work, he's never shown up without knowing his lines. He's not flawless, but he never slows down the set, never yells at people."

Is Mad Men likely to be as good as it gets for this cast and, if so, is that feeling bittersweet now that they have wrapped the penultimate series? "It probably is as good as it gets," says Kartheiser. "I'll be sitting with John Slattery [who plays the wise-cracking Roger Sterling] – he's been around this industry since the dawn of time and he'll still look at me and say, 'Man, this stuff is great… can you believe how great this work we get to do is?' But I wouldn't say it was bittersweet at all. In our job, all jobs always end and there's always something new and exciting ahead."

In the break before filming the sixth season, Kartheiser was on stage in San Jose, playing an agoraphobic novelist in The Death of the Novel ("a turgid potboiler of a social-issue play", according to the San Francisco Chronicle theatre critic), and making a couple of small independent films that he reckons will never earn a release. "I think I actually ended up paying money to be in them," he says.

His role in Mad Men hasn't, in short, opened any magic doors into the Hollywood mainstream. "I'm auditioning for cameos in two different films and I'm sure there will be hardly any money on the table. I don't want to talk my price down but that really is the case. Even big, big stars don't get paid a lot of money for big, big roles any more, and I don't think there's a big fan base for Pete Campbell out there begging to see me on the big screen."

Kartheiser certainly doesn't live like a movie star, although he says he has a few more possessions since he was interviewed at home in his one-room bungalow West Hollywood in 2010, when his "wooden box" was devoid of possessions and amenities – including, apparently, a lavatory, which has now been installed.

"Most of my house is still pretty empty," he says. "When Mad Men started it became such a success that people started sending me stuff, just boxes of shit, and I thought 'I don't want this stuff.'" The subsequent de-cluttering became fairly extreme, he admits. "Although it's not quite as possession-less as it used to be three or four years ago… I have a few more items since then."

Could the sudden appearance of creature comforts be anything to do with his relationship with Mad Men co-star Alexis Bledel, who played Beth Dawes – the depressed housewife with whom he had an affair in season five? Are they still a couple? The till-now prolix Kartheiser clams up and confines himself to a one-word answer: "Yes." End of story – or not, as the case may be, because about a week after he's cagey with me, his engagement to Bledel is leaked to the press. They hope to get married in the autumn.

After years of taking public transport and, amazingly – for this is LA – actually walking places, Kartheiser has also now bought a car. "I finally bit the bullet two years ago. It got more difficult having to talk about my job with strangers on the bus. You don't want to spend an hour of every day talking about yourself to someone you don't know.

One person recognises you and then everyone else is like, 'What do you do, man, you on TV or something? What does that pay?' It was happening more, especially as I was taking the bus home from work and I had my hair set for the part. Now I get about three parking tickets a week and a speeding ticket a month… it's really great."

That little sarcastic coda sounds just like Pete Campbell. How much of him is there in the character? "How much? All of Pete Campbell is in me. It's not written by me but it's interpreted by me – the interpretation, I take credit for. You can never escape yourself too much – no actor can."

'Mad Men' season six begins on Sky Atlantic on 10 April

Masterminds

Kartheiser's first starring role came in this 1997 movie, in which he played a troublemaker taking on a criminal gang

Another Day In Paradise

Kartheiser graduated to adult roles in Larry Clark's 1998 film, in which he played a drug addict and small-time thief

Mad Men

Kartheiser as Pete Campbell, dancing with Alison Brie, who plays his wife Trudy, in the sixth season of 'Mad Men'