Two years ago I asked someone I knew why he was growing a silly moustache. I didn't say silly. But it was. It didn't look like a moustache he would grow normally. It looked like a novelty moustache. It curled down the corners of his mouth; a moustache a bad guy might grow in a western. It was, he said, for something called Movember. You grow a moustache in November, and get people to sponsor you. The money goes to a prostate cancer charity.

This year 75,000 British men have registered, and it's a more interesting thing than you might think. Men are making themselves look silly – of course, in some cases they look fine, or even cool, but this is rare – in order to help other men who have fallen ill. But it's not just men who are ill – it's men who are ill in that embarrassing area that makes men so vulnerable. It's that illness that men, who famously won't go to the doctor, won't go to the doctor about. And then, when they do, it might be too late, and they might need radical surgery, and then they might have to face the nightmare scenario.

Yes, they might have to face the nightmare scenario of not being able to, you know … As a man, it's hard to type the word that a doctor would have to use if he'd performed radical surgery on a guy's prostate. Because not being functional in an erectile sense, for men, is unthinkable. That's why they don't go to the doctor. Because they don't want to think about it. And that's why people are growing silly moustaches.

But they're not trying to save everybody. Just other men who are vulnerable in this way. Here, men are behaving not like men, but like any other community. Like gay people. Like black people. Like women. Like a minority group. They are standing up for their own. The men's movement writer Warren Farrell once told me that "men's weakness is their facade of strength". And it looks as if men are beginning to drop that facade of strength. Which can only be a good thing, right?

Well, I think so. But I don't always feel it in my gut. Drop your facade of strength: that's an unusual message to deliver to a man. These days, as a man, someone is always giving you a message. And the messages are mixed. They're confusing. Be a man. Man up! But also: get in touch with your feminine side. And: for God's sake, whatever you do, don't get in touch with your feminine side! Be strong, bordering on feral. Be metrosexual. Be a bit camp. Only real men aren't afraid to be a bit camp. On the other hand, be a man of decisive action. Drive fast, like Jeremy Clarkson. And don't be afraid of offending people. Don't be a hand-wringing wuss! Women will only like you if you're ultra-masculine. But: women will only like you if you're a New Man. If you're sensitive. If you listen. If you wear some kind of perfume. So drop that facade of strength. It's actually your weakness.

Last year I attended a conference of psychiatrists. They were mostly men. At one point, the discussion turned to a Freudian analysis of the economic crisis, and it all came out – how the crash was really a function of men and their dicks. Investing, goes the theory, is a bit like having an erection. It depends on confidence. There is an element of hoping for the best. When you have sex, or invest money, you expose yourself to risk. It's crucial not to entertain thoughts of a market crash. When the crash seems inevitable, your only remedy, as a man, is to deny it.

So men, by having dicks, caused the global financial crisis. I jotted it all down. It felt, at the very least, plausible. Afterwards, the audience made comments. I told an anecdote about the boss of one Wall Street bank who had a dispute with the chief of the New York Federal Reserve. "He thinks he's got a big dick," said the boss, a man's man, whose bank, Bear Stearns, was about to crash. "But he's got nothing."

The audience laughed, and I passed the microphone back, savouring the moment – the warm, familiar glow of anti-male laughter. Men ruined the economy! They think with their dicks! It would be hilarious, if it wasn't so sad.

As the feminist writer Susan Faludi famously wrote, in her book Stiffed, in the latter part of the previous century, all over the western world, men felt betrayed. All the things they had been trained to do, for thousands of years – heavy lifting, agricultural work, killing people, hunting animals and seeking out new frontiers – had stopped being so important. Space was the final frontier. Guys went up there, said Faludi, and saw that, as a frontier, it was pretty much a dud: "There was no one there to learn from, or to fight." The world the astronauts came back to was subtly different. It was no longer a world where men had to be men. They had to find something else to be. They didn't know what that thing was. They still don't.

For decades, we've been bumbling around, not quite sure who we are. All the time, the culture at large seems to be reminding us what idiots we are. When I started reading children's books to my son, I began to notice something. All the male characters seemed to be idiots. The Gruffalo was an idiot. Duffy Driver was an idiot. Tiddler was an idiot. The male characters seemed to be careless, stupid, greedy or selfish – the fish that gets lost, the dad who won't tidy the house, the dad who doesn't listen. On the other hand, the female characters were resourceful and smart. Just look at Marge and Homer. If Marge was a greedy fool, and Homer was a decent, sensible guy, it wouldn't work, would it? And am I wrong to think that male characters in movies are becoming more childish? Are films such as The Hangover and Knocked Up trying to tell us something?

Are we being bashed because we're strong – because we can take it? Are we being bashed because somebody has to be bashed, and we're stepping up to the plate? Or is it because we deserve it? Is it because of centuries of patriarchy, of always having to be right, of killing people, of never listening, of sexism, of always wanting to be in charge, no matter what, of grunting and snoring and forgetting anniversaries – of all those centuries of never asking for directions? Is it because we need to have some sense bashed into us?

And here's another thing. If men aren't suited to the modern world, women are. They are famously better at multitasking, which makes them good with computers. At school, they pass more exams. They are better with words. When they invest money, they are less aggressive. Yesterday David Cameron said that if there were more women in British boardrooms we would have less of a problem with excessive pay. If women had been in charge of the economy, would we be in the mess we're in now?

Last year, the American journalist Hanna Rosin said something that really hit home. Forty years ago, an American biologist called Ronald Ericsson found a way of separating male sperm from female sperm. This meant that, at some point in the future, people would be able to choose the sex of their babies before conception. Feminists were alarmed. They thought that everybody would want boys. They needn't have worried. As time goes on, more and more people want girls. Four decades on, the numbers are dramatic: Rosin reported that people who plan to use Microsort, the newest sperm-sorting technique, show a 75% prejudice in favour of girls.

This is really something. Think about it: for the whole of human history, people have wanted sons. In most parts of the world, they still do. Think of all those kings, pacing the stony corridors of their castles with their fingers crossed as their wives went into labour. Think of Henry VIII! "Men in ancient Greece," says Rosin, "tied off their left testicle in an effort to produce male heirs; women have killed themselves (or been killed) for failing to bear sons." And now, at least in developed western nations, that could soon be gone.

Rosin interviewed Ericsson, who told her: "Women live longer than men. They do better in this economy. More of them graduate from college. They go into space and do everything men do, and sometimes they do it a whole lot better. I mean, hell, get out of the way – these females are going to leave us males in the dust."

Are men having a crisis? Men are not particularly comfortable discussing this issue, for obvious reasons. So I talked to women. They nearly all said the same things. Don't forget: men still earn more money than women. Most CEOs are still men. Most politicians are men. I spoke to feminist writers Naomi Wolf and Natasha Walter. I mentioned the male crisis. I said how women seemed to be better suited to the modern world. "I see it," said Wolf. "I see the reasoning. But I don't think that everybody should be celebrating. It doesn't change the bottom-line economic reality."

Walter said: "It's still very much a man's world. The wealth and power is concentrated in the hands of men. I'd hope it was the start of a more equal world." This was the female position. Men have been controlling them and objectifying them for millennia. Now, things are looking a little better. But don't count your chickens.

So let's not. But I can see some positive signs. Research published this week suggested there are now 10 times more stay-at-home dads in Britain than a decade ago, with one in seven fathers the primary carer.

Some of these dads reported finding this hard, and wished they earned more money than their partners. But still, it looks as if men are beginning, just beginning, to take themselves less seriously – or to take different things seriously than they did in the past. Maybe they are beginning to lower that facade of strength a tiny bit. Movember might be the start of a new era.