The word "change" rings through fashionable rhetoric. Barack Obama promised it. This week, David Miliband (whose aspiration to be a British Obama echoes Obama's to be a black Kennedy) plagiarised it, as has David Cameron. Voters seem to respond favourably. But why?

If history is anything to go by, people crave stability in times like ours, when the pace of change is madcap. When we reel from "future shock" we reach for the comfort of the familiar. So what makes change attractive to people who, by rights, ought to be sick of it? Is the "change" voters applaud just reactionary yearning in disguise? Or do we crave difference because we are desperate?

Maybe what we really want is a change from change itself. evolution programmed humans to be conservative. Golden-age illusions about the past inspired most of the world's great revolutions. The Reformation was an attempt to recreate the apostolic Church. The "liberty, equality and fraternity" the French Revolution sought were ingredients philosophers ascribed to primal times. even people who like to change jobs or homes or partners usually seem to revert to type or grasp for lost loves.

If we did want to escape from our present, it would hardly be surprising. No previous generation has experienced the accelerating pace of change ours has endured. Almost all the current connotations of change are negative. Look where it's got us - economic ruin, environmental overkill, moral collapse.

In the 20th century, optimism failed. Utopias proved elusive or ended in genocide. Planning for progress inflicted misery on people imprisoned in tower blocks and impoverished by command economies. Somehow, in the 21st century, we retrieved hope from the disasters. But now our confidence that we can manage change for the better is collapsing again.

We have made progress in technology and medicine, but every advance has brought its own problems, from antibiotic-resistant superbugs to undisposable nuclear waste. Processes that promised progress - globalisation and democratisation - have disappointed. Globalisation increases inequalities. Democratisation leaves evil regimes intact and brings incompetent ones to power. environmental change is unsettling, because for most of the recorded past, climate change was relatively slow and the loss of biodiversity unspectacular. Now the Aral Sea is turning to desert, parts of the Arctic to water, and oil is becoming an expensive rarity within the span of a single lifetime.

Cultural change is even more insidious as whole countries become unrecognisable to their own people. Would timetravellers from Fifties Britain recognise their bawdy, gaudy successors? Fear of the forfeiture of traditional culture is powerful - accounting for much current hostility to immigration.

So - more change? "Back to Basics" and "Family Values" - especially where electorates are sick of involvement in unjust wars and restive for want of a moral compass - look, from the perspective of history, like better slogans for a chaotic age.

Yet change is still politically saleable. I see three reasons for this. First, change is as appealing as an astrologer's promises - vague enough to mean all things to all people. Second, its popularity points to widespread fear that we've hit rock bottom. Voters' susceptibility to it is a triumph of hope over experience - faith that no change could be worse.

Most of all, the rhetoric of change works because politicians are the only group exempt from the changes of recent times. Tony Blair, for all his nonsense about "newness", was Thatcher in trousers. Gordon Brown's "prudence" was an abjuration of adventure.

Clinton and Bush seem like opposite personalities, but they both subverted the constitution, arrogated power to the presidency and sold out to multi-billion dollar lobbyists. As Gore Vidal once said, there are two parties in America - conservative and reactionary.

No change of government shakes the continuity of the political class. The same has become true of Britain. To the electorate, voting for change equates with repudiation of the damnable political cosiness which has brought so much distress to everyone else.

Environment

This is the summer that our attitudes to energy - and with it a host of green issues - changed for ever. The price of oil has rocketed; it has eased a little recently but it's still double what it was a year ago, while gas and electricity bills are surging. The era of cheap energy is gone for good.

We may well be almost at the peak of oil production, but competition from China and India means our petrol will never be as cheap as it was last year.

We're responding by driving less - petrol consumption is down, sales of electric cars are booming, and almost two-thirds of drivers say they're considering public transport instead.

We're also recycling more and turning to gizmos such as low-energy lightbulbs, whose sales are set to double this year. But at the same time, there is a new awareness of the problems caused by our use of energy - above all, the carbon emissions that cause climate change.

Combine the energy squeeze on our wallets and worries about climate change and it's not a happy combination - but it does at least mean that we're moving in the right direction for the planet.

Technology

In the gadget world, Apple's iPhone has been the catalyst for a change in the mobile phone industry, giving people true internet access on the move, while building on the firm's hugely succesful iPod brand.

With its multi-touch screen, virtual keyboard, in-built iPod and camera, the iPhone has sold more than four million worldwide since being launched in June 2007. In fact, the past 18 months have seen the technology world become more sociable. The incredible rise of Facebook, personal blogs and Twitter have seen a shift away from content created by big corporations to a more personal approach.

Even politics has not been immune, with Facebook and Twitter campaigning now standard for almost every politician, and David Cameron taking things a step further with his webcameron site.

"Politics is absolutely a key part of the general cultural change that the internet has brought about," said Sam Roake, Cameron's web guru. "Opening up like this involves a certain amount of risk but we're confident that on balance it's going to be a great thing - it heralds significant change in the way politics has been done."

Of course, there is a downside - coming in every morning to a list of the people who've electronically poked and bitten you soon becomes incredibly irritating. But as the sites become more sophisticated, it seems the spread of social networking might have only just begun.

Lifestyle

Wd b gd 2 c u. What the hell does this mean? Arguably our biggest lifestyle change has been the way we communicate with each other. The growth of texting and on-line networking sites means you can have a relationship without ever meeting the other person. The past 12 months saw a 30 per cent surge in texting in Britain. I have been seduced by text, dumped by text, even had my mortgage renewed by text.

What's fascinating is how the "forever forty" generation embraces diversity in a way that would be unimaginable to our parents. We wear fashionable clothes, eat out, buy the Radiohead album. At 45 you could be a grandparent, going to university for the first time, having your first baby, or dating again after a long marriage.

And friendship is the new love affair. Unlike our parents we are hugely ambitious for relationships outside the family. Friends make us happier, more independent than any other relationship in our lives.

We kid ourselves that we're still young (that great term " midyouth") but actually there's a huge chasm between us and today's 20somethings. They process information differently, faster; they edit out content that bores them.

What worries me is the false intimacy of 21st century lifestyle culture. We all know the hot, dirty thrill of hearing a new message ping into our inbox at 4am. But have we lost the art of speaking face to face?

Clarity is certainly no easier. We hurt and confuse each other. Make absurd value judgements. Because tone is impossible to judge by text or email. Who says the important things in life should be reduced to 150 characters?

Finance

Another change that has brought home to the UK the shifting order is the credit crunch. In the financial equivalent of the "butterfly effect" - a butterfly flapping its wings on one side of the world and altering the path of a tornado on the other - a homeowner with a dodgy credit record "subprime" in the American Midwest seeks to top up his mortgage. The lender lets him have the money even though he is already heavily borrowed. The loan is packaged up with hundreds and thousands of other such loans and sold on to banks in London and their clients for them to trade as a form of investment.

When the US householder and others like him hit hard times and defaults, the UK investors are left nursing huge losses. The banks don't have as much money to lend and are scared of committing themselves. People here suddenly find they can no longer obtain mortgages. It's not down to anything they've done but to something that began on the other side of the globe.

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