In 2011, political correctness finally went mad. Really mad. It got angry with Ricky Gervais for using the word "mong"; it shouted at Jeremy Clarkson for saying that strikers should be shot; it had Andy Gray and Richard Keys sacked from Sky for being sexist about female match officials; it forced Ofcom to censure Frankie Boyle for his jokes about Jordan's disabled son. Maybe mad is the wrong word. PC got hardcore.

Berating people for revealing private prejudices in public, for picking on someone less than their own size, for making out-of-order gags… PC became so central to the nation's conversation with itself that I started collecting articles. Such as: "White officers sue Met for 'racism'" (they were charged, then cleared of race-related offences, and sued the Met for compensation). Lots of pieces on how Christianity is under threat from PC, or whether a comedian's joke is "bad taste". Blogs and counter blogs about how women are represented in computer games, whether on-pitch slagging between football players should be legally monitored. Many articles linked the BBC with political correctness – the furore about the Beeb proposing to stop the use of BC and AD (overly PC); the fuss about the lack of females on the shortlist for Sports Personality of the Year (not PC enough).

To be honest, I found it all quite exciting. A tussle is always fun and it seems as though this tussle, this argy-bargy about how we treat each other, the terms that we use, how we acknowledge (or don't) the differences between us, is one that is of the moment and, for this moment, up for grabs.

"I can remember when, if you fancied someone, you had to negotiate getting a date by somehow indicating that on no level at all were you interested in that person sexually. That was the only way of doing it. If you did that now, the girl would be insulted. People have no problem with someone saying they're sexy now. It would be an insult not to say you fancied them. Back then, it was sexist…" I am talking to Stewart Lee. Stewart is not only the UK poster boy for PC comedy, he is around my age and thus, like me, remembers the mid-80s, when PC first roared. Back then, at the height of Thatcherism, being politically correct – being "sound" – was all-important to anyone young, left-wing and not in a position of power. I took to it like a Tory to the Bullingdon and to show my "cred", I covered my bedroom wall in postcards. I've still got them. There's one that showed Margaret Thatcher dipping her hand into an elderly lady's purse; another that reads "The hand that rocks the cradle should also rock the boat". One depicts a clenched black fist in front of an ANC flag; another is a picture of a woman saying to a man: "Oh, my parents were murdered when I was three, right before I was taken hostage…" and the man saying: "The solution to your problems is between my legs." Which I still think is funny.

Back then, PCness was so central to our studentesque sense of self that our college passed a resolution to ban the Sun from the common room. I forget what for – probably Page 3 (I know, crazy) – but anyway, the Sun wrote back and told us we were right-on pious fools and that Britain's Brightest Read didn't need our custom anyway. We laughed, but we were shocked. We wanted very much to be taken seriously.

For, in the 1980s, PC was very serious. It didn't do jokes. It agreed political motions, usually after hours of grim huffing. And it came wrapped in a peculiarly British social anxiety. As a PC person, what you really didn't want to do was offend anyone, especially those who had it tougher than you. If you were guilty of any of the following character crimes: being white, being able-bodied, being middle class, being heterosexual, possessing a penis, you were, by definition, an Oppressor and thus compelled to sympathise with the pain of those who were not. So: sorry was the easiest word. Sorry for your being black, or gay, or a woman, or in a wheelchair. Sorry for me not being any of those things. Sorry about that.

Stewart (an Oppressor, obviously) remembers doing a stand-up set in 1989. "I made a joke, a surreal thing, about going to the doctors and saying I couldn't meet women and then going on an aquatic safari because the doctor thought I said 'whales'. I got heckles from people, saying: "Sexist!" Clearly I wasn't being sexist. I'd just mentioned the word women."



Today, when I sit upstairs on the bus, I hear kids talking to each other in a way that would make my 80s self shudder. I live in south London in an area that estate agents call "vibrant", which means there are a lot of different races and classes living close to each other. This is some of what I hear on the bus: "dirty African", "white boy", "my nigger", "batty man", "bitch", "ho", "lighty" (to light-skinned girls). But rarely does anyone seem to mind. (The insults can be quite random: I overhear one chat between a couple of kids where one disses the other's mum – "Your mum is fat!" – and then immediately retracts. "She goes down the gym, that's good.")

A few years ago I had a conversation with my stepdaughter, who talked me through some teenage slang. The term I remember the most vividly is "gash", meaning "females". "If there's a lot of girls in a place, then," she said brightly, "you say: 'There's bare gash.'" I was genuinely shocked by that. She didn't understand why.

Clearly I'm too old to know what teenage slang is any more. So I visit Live magazine in Brixton to talk to some of the young people who produce it. They, too, are bemused by my worries over "gash". Wesley Cox tells me that it's out of date ("I ain't even heard that word for at least two years"), but none of the six people I talk to – whose ages range from 15 to 23 – understand why I might find it offensive in the first place. When I explain that, to me, gash is obviously a nasty term for a vagina and so it's reducing a woman to her (hateful) genitalia, there are nods. But they still don't really find it a problem. Neither is "gay", meaning rubbish.

"Bitch" and "nigger", however, start a discussion. Christian Adofo points out that a lot of people who you wouldn't expect to talk street slang – "like Prince Harry" – do now because of Dizzee Rascal breaking through, and they can get it wrong and cause offence. Wesley says that if someone he doesn't know, black or white, called him nigger, he would have a problem. But he's fine with his friends doing it. "I call my white friends my niggers. They're my niggers – they're my friends."

Fiona Anderson has a gay friend who calls her bitch, which she doesn't like, but accepts, though she wouldn't accept it from a stranger. Jeana Povey, who prides herself on speaking correct English, hated it when a mate referred to her as her bitch, even though she was doing it to be nice: "She did it on Facebook – she said: 'You're my bitch for life!' I just replied: 'Oh I love you, too.' She got the message." (Incidentally the worst thing Jeana thinks she's ever been called was "posh": she thinks it's ignorant, when she comes from Peckham and chooses to speak in the way she does.)

All of them, even those who reject slang entirely – Josh Grey says: "People who use slang all the time can't speak formally when they need to" – are firm about meaning coming from intent. It's how you say what you say, and who to, that matters. That's far more important than a word's roots. (It strikes me that this is a microcosm of how a racially mixed community works: no one really cares about your background, if everyone's getting on. But if there's a row, then language gets specific, and dark.)

Finn Grist, who at school was called white boy by his Indian, Pakistani and Sri Lankan mates, is aware of the Ricky Gervais debate. He has no problem with what he said. ("What's a mong, anyway?" asks Wesley. I explain. One of Wesley's sisters has Down's syndrome.) Later, I recall that during Sachsgate, Radio 1 listeners were the only users of the BBC who didn't think there was anything wrong with Jonathan Ross and Russell Brand's answerphone messages to Andrew Sachs. The listeners could tell that Ross and Brand didn't mean to be horrible. And anyway, the messages were funny.

Comedy is tightly wound around today's PC debate. Not only because it's the get-out-of-jail-free card for the non-PC wit ("It was a JOKE! Where's your sense of humour?"), but because comedians, in general, have become more prominent within UK culture and many comics like to push at the boundaries of whatever is currently deemed acceptable.

I speak to Stephen Armstrong, a journalist who writes a lot about comedy, and he points out that for many stand-ups, the best kind of laugh is the one followed by a sharp intake of breath: "A kind of involuntary laugh, followed by shock at yourself. The audience laughs and then thinks: 'Oh no, that's awful – I shouldn't have found it funny!'" It's that laugh that comics like Frankie Boyle are searching for.

There's another type of laugh, he says, that comes when a comedian gets big. Al Murray is an example. When he first aired his Pub Landlord character, Murray's audiences understood that the landlord was meant to be laughed at. But as he got more popular, the audiences grew to include people who laughed with the character, too. The pub landlord was saying stuff – rubbish jokes about the French, or women – that they wanted to be able to say themselves.

Stewart Lee talks about this, too, and tells me that it's why he tries hard to perform "in an alienating way", and he often deconstructs his jokes so that no one can get the wrong idea. He also says that he was asked by Katie Price, aka Jordan, to speak on a documentary about the Frankie Boyle affair. He refused. "Comedians create an intimate atmosphere, even if they're talking to a thousand people – that's the point of what they do. And that's the context. You can't take a joke out of context and use it to beat up the comedian, even if you don't personally like it. And I don't want to be someone who advocates banning words. What you hope is that people will use them responsibly."

Either way, whether comedians are playing with our sense of taboo or taking the mickey out of the bigoted, they generally know what they are doing. "They're good at their jobs," says Stephen. "Good comedians are really clever; they instinctively know where you can't go. But the bleed-off from that is fans who follow the trajectory of the joke to a dangerous place.

"So a comic on stage might say something about women, and then people take it as a cue to go out and be really sexist. Or they make a joke that tests what you think about disabled people, it's shown on YouTube, and a kid in a wheelchair gets bullied. It's like black belts in karate: they know which punch can kill. But if everyone thinks they can kill with one punch, they just end up twatting other people for no real reason."



Political correctness is a big subject. So I decide to follow one strand of it. What have been the PC talking points for women since the 1980s? One of them, I think, is the Women are from Venus approach. In 1992 relationship counsellor John Gray launched his book Men Are from Mars, Women Are from Venus, and its central idea – that men and women deal with life, especially emotional life, differently – has formed the tick-tock heart of innumerable magazine articles ever since. How baby boys are boisterous and straightforward, girls complicated and quiet. How men want sex and women cuddles (or chocolate, or shoes).

It was followed in the UK, in 1994, with the launch of Loaded magazine (first cover: Gary Oldman, with the word LADS written underneath). Loaded was a sparky reaction to PC, a generational swing away. It celebrated daftness and humour and women who forgot to put on their trousers. It expressed in print what many men said in private, which was often not nearly as PC as their mums might have hoped. Then, in 1998, we got Sex and the City. It was frank about female sexuality, the way women spoke to each other, what they wanted from sex and relationships. And it, too, emphasised the differences between the sexes. Even though, to an outsider, a neurotic New York man would seem to have much in common with a neurotic New York woman.

But the real game changer was Big Brother. In the 10 years Big Brother was on Channel 4 (from 2000 to 2010) it altered everything, and not just for women. By revealing how people act and speak in private, it showed that British people are more open-minded than the nation's press thought. The public voted Brian, a gay man, to win in BB2. They voted transsexual Nadia as winner in 2004. And, through Jade Goody, whose celebrity career was launched when she came third in BB3, the public made it known that sexism is not the worst of PC crimes – racism is.

In 2007 Jade was thrown off Celebrity Big Brother for her racist bullying of Shilpa Shetty. She herself had been bullied, in her life and in the BB house, for being lower class and female, but racism absolutely trumped that. Big Brother revealed that there is a hierarchy in PC. It is ludicrous to have a victim competition and it seems right that racism is the number one offence, but perhaps all those years of gender clichés, the teasing and the jokes, made sexism seem more trivial, less of a concern. In the 1980s motherfucker was deemed the most offensive word by TV viewers. Now it's the N word. Bitch, slag, ho, sket… they don't even come close.

Though you can get downcast thinking of how women are represented in the media, or how there are so few out gay men in sport, or how it took until for 2001 for a black woman – Halle Berry – to win a best actress Oscar, for those of us who believe in PC there is no doubt that things have changed for the better in the past 20 years. No longer do we get articles such as the one in the Sun in 1986 entitled: "Twenty ways to spot a homosexual". My brother reminded me of that. His partner remembers another one called: "How to dance like a gay man". These seem funny now but weren't so hilarious at the time.

I talk to Kevin O'Sullivan, TV critic of the Sunday Mirror, who worked at the Sun in the 1980s under Kelvin MacKenzie. He clearly remembers the tabloid's fascination with all things gay. "It was seen as something exotic, titillating," he says. "I'm not sure the readers were that interested, but for some reason the tabloids were." He tells me about a time when he was working on the Sun's showbiz desk and a story came in that EastEnders was about to introduce its first openly gay couple.

"Kelvin came round, going: 'What you got?' And I told him, because it was what I was working on. He went away and said: 'Right, that's the splash' [the front cover]. You can guess what the headline was: 'Now It's EastBenders!'"

Kevin says that tabloids have changed – he describes a hard core of older men with outdated attitudes who have pretty much disappeared from the red tops now. But, he says, the main change is in the readers. Recently, for instance, readers have told tabloids in no uncertain terms that "bonkers" is no way to refer to someone suffering from mental illness and, says Kevin, "all papers live in fear of what happened to Jan Moir. Even the Daily Mail worries about that happening again."

Moir, a Mail columnist, wrote a nasty piece after Boyzone singer Stephen Gately died, making smearing assertions about his dubious – for that read gay – lifestyle. Twitter was very quick to mobilise response and the Mail website almost collapsed due to the amount of outraged comments left about Moir's articles. (Since then it's clear that the Mail uses PC to test its readers: it jumped on Jeremy Clarkson's strikers comments and recently ran a headline about Jimmy Carr telling a "sick" Down's syndrome joke – he didn't – that was by no stretch of the imagination a news story.)

Ah, Twitter. Bastion of the liberal-minded, home of the PC. Though you get a huge variety of opinion across the site, the most powerful people on Twitter are, mostly, right-on vigilantes (digilantes). They get cross with anyone who expresses a right-wing view, let alone someone who makes an off-key joke about women or gay people. Or "mongs", as Ricky Gervais did.

Gervais, who is clearly not a bigot, nevertheless genuinely upset many people, and he didn't do himself any favours by posting up pictures of himself making stupid – "mong" – faces to go with his tweets. First, he disobeyed current comedy's golden rule: you can only make jokes about something you have direct experience of. You can't reclaim a word, or make a gag, if it's not yours in the first place. Second, he thought that everyone in Britain was nicer than they are: he assumed that no Down's syndrome children ever get teased or beaten up or have stuff chucked at their front door. And third, he was new to Twitter and thought he was just having a laugh with some friends.

The distinction between public and private has become very blurred. That's Twitter's USP: your kitchen-table banter, broadcast to the world. The public and the private, cosying up. Fine, but it can be hard to indicate tone of voice in a tweet (or a text). Hence emoticons. There's an old joke (told by a man) that goes: "If women could hear every one of men's thoughts, they'd never stop punching us." Twitter sometimes reminds me of that.

But even Twitter isn't anywhere near how we talk to each other in real life. I think about how I talk with my husband, the jokes I make about him being Irish, the slating I get from him for being from Manchester. Not because I'm anti-Irish or he hates Mancunians, but because, in this country, slagging someone off means you like them. Calling someone a twat might mean you think they're a twat. Or it might mean you love them a lot and think they're the exact opposite. It's all about how well you know them. Which can be hard to judge in itself. Plenty of people get hacked off because an acquaintance gets too cheeky too soon.

Sometimes it seems as though PC is a never-ending moral exam with endless permutations to catch you out. If football player X calls football player Y a black bastard, should he be reprimanded? What about if X calls Y's mother a whore? What about if he says the same thing about his sister? Or his 12-year-old daughter? What about if he called her a white whore? What about if X and Y are cousins, does that make any difference? What if they're from different countries?

Perhaps it would be easier if, like the old adage has it, everyone refrained from making personal remarks. As if that's going to happen. Not only do we want to be informal with each other – it's friendlier – today's world is deliberately becoming more and more personal. Every commercial purchase tailored to our particular taste; everyone proclaiming their likes and dislikes; our profiles announcing to the world just who we are and where we think we fit in. Forget privacy: personal – access to the real you – is where we're all going.

So perhaps we should all adopt the kids-on-the-bus attitude: accept that everyone is different, make jokes about it, but don't take offence unless it's meant. As Finn said to me: "It's about how you take a word, as much as what people mean by it. It's just words." How personal do you want to get?