Can't decide which cereal to buy from the 275 on the shelf? That's because there are just too many of them, says psychologist Barry Schwartz. And it's not only in the supermarket that consumers are feeling overwhelmed and stressed. Harriet Griffey meets the man who wants us to limit our choices

At a café near the British Museum in London, there's an enormous choice of sizes and strengths of cappuccino, espresso and latte. But Barry Schwartz, the author of The Paradox of Choice, has no problem - a decisive order for an Americano and he's done. Which comes as something of a relief, given the problem he has had selecting a pair of jeans in the past.

Schwartz, a psychologist and professor of social theory and social action at Swarthmore College in Pennsylvania, has flown in to participate in a seminar at the Royal Society of Arts, and also - by invitation - to give the benefit of his expertise to the Prime Minister's Strategy Unit. It is difficult to imagine what a Strategy Unit is: almost as difficult as it is to imagine this slight figure in his duffel coat being invited to advise it, until he begins to explain the subject of his new book and how it was written after wrestling with the problems of choice in a well-known jeans outlet.

"I went to buy jeans, and I just wanted regular jeans, the kind that used to be the only kind for years. I discovered that they didn't exist any more, but there was slim fit, relaxed fit, easy fit, tapered, slim leg, boot cut, button fly, zip fly, acid washed, stone washed, distressed..." and he gesticulates in a hopeless fashion.

But where's the paradox here? Surely all this choice is good? (Although, admittedly, his confusing experience is starting to ring some bells.)

"Well, what had been a five-minute operation," Schwartz continues, "had now become a major project, which is bad enough. But what was worse was that I realised that I suddenly cared about how well my jeans fit me, in a way I'd never cared before. I ended up with a pair of jeans that no doubt didn't fit me better than any jeans I had ever owned, and I was less satisfied than I had ever been before because, if there were all these kinds to choose from, there ought to be one kind that was perfect - and as far as I could see, there wasn't.

"And that's what triggered me to look at this paradox that surrounds choice. Because I realised that the more choice we have, the less satisfied we are likely to be."

What Schwartz, 58, also realised was that he had struck a nerve. "There's a lot of interest in this paradox, and when I talk about it there's a look in people's eyes of instant recognition - that I've pointed to something that's really been driving them crazy, although they didn't know what it was. So I win an audience over in about 30 seconds flat, unlike with anything else I've ever done. It usually takes a long time to convince people that what I'm talking about is worth worrying about, let alone that I'm right," he says wryly.

The myth we seem to have bought into is that if choice is good, more choice is better. But no, Schwartz says: this mantra of the 21st century - applied to all manner of choices - gives rise to anxiety, unhappiness and even clinical depression.

Just think about the choices we make every day, whether it is the food we buy from supermarkets, with their 300,000-plus lines; the schools we choose to send our kids to; the cars we select to drive; the phone service we opt for; the healthcare plans; the pension options; where to take a holiday - the multiplicity of choices means that we have to research, consider and decide what we want. Choice has become an all-consuming task, but it doesn't necessarily improve the service or the product. Take telephone directory enquiries, for example. It used to be so simple - one number, one service. And it worked. Now we have a number of services, none of which seem capable of finding the number you need.

"I've attempted to explain why and when an excess of choice becomes a problem," Schwartz says. "When you have all these choices, you have an enormous problem gathering all the information to decide which is the right one. You start looking over your shoulder, thinking that if you'd made a different choice, you'd have done better. So there's regret, which makes you less satisfied with what you have chosen, whether or not there's good reason to have regrets. It's easy to imagine there was a better option, even if there wasn't really, because you can't possibly examine all of them."

This may be hyperbole, but Schwartz also makes the point that while we will accept what's "good enough" in some cases, we will strive for the best in others. But he makes a general distinction between those of us who are "maximisers" and those who are "satisficers". Maximisers never buy anything without checking out all the options and researching all the available material, but they still feel dissatisfied. Satisficers set themselves a choice, but within limits, and mostly they end up with something they are happy with. But what is important here, it is Schwartz's impression, is that choice actually turns us into maximisers.

"So I suggest that people should learn to be satisficers, but it's important to qualify that this isn't the same as putting up with your lot and tolerating what's not good. It's more about just being happy with what is often good enough. It's a simple analogy, but if you like cornflakes for breakfast, have cornflakes rather than thinking that you have to choose one of the 275 varieties of breakfast cereal on offer. When it comes to breakfast, it's good enough.

"However, if there's one area of life where people find that impossible, it's as parents. Have you ever heard a parent say, 'I only want what's "good enough" for my child?' No, we all say we want the best for our children. So young parents in the States, especially highly educated ones, drive themselves crazy finding the best pushchair, the best bottle, the best daycare centre, the best everything, because what could be more important than your children?

"Not only does this create a kind of stress and burden on parents - which risks making them less good parents because they don't have the sort of psychological and emotional resources left to just enjoy being with their kids - but it does something else as well. It teaches children to approach their own decisions in the same way. You know: 'If my parents are obsessing like this about every little thing I come into contact with, maybe this is the way I should approach the world.' So, quite inadvertently, I suspect parents are teaching their children to be maximisers, and afflicting them with the same sort of anxiety about their choices."

Schwartz goes on to illustrate this with a simple story from his own family. "My granddaughter, who is four, went shopping with her mother and went to buy a new toothbrush. She had about 20 to 25 of them to choose between, with characters from kids' TV and things, and my daughter - thinking she was doing her daughter a favour - said, 'Which do you want?' And this created a massive problem for my granddaughter, who became completely paralysed, until finally she said, 'Mummy, you choose.' It vividly demonstrated to me that we're not doing our children a favour by giving them the world on a platter. Just give it out bit by bit, so they can learn to deal with it bit by bit."

Another important aspect of excessive choice, Schwartz says, is the time it all takes, which consequently takes us away from what does make us happy. "We know that what makes people happy is close relations to other people and meaningful work. We have research that confirms this. Intimacy, closeness to friends and family, and work that you get satisfaction out of seem to be the most important contributors to personal happiness, once you have passed a subsistence economic level. And these things take a real commitment in time. You can't have relations with friends and family that mean anything unless you're willing to give it some time. It's a commitment, and it's one worth making, but if you spend three hours on the internet trying to decide which digital camera to buy, then those are three hours that you're not spending hanging out with your partner."

Excessive choice options may be affecting romantic relationships as well, Schwartz thinks. People who are maximisers will, by nature, find intimate relationships tricky because not only are they endlessly on the internet researching their next purchase, but they also believe there might be a better relationship out there. "This is speculative, and we are doing research on it, but I think that this attitude has an impact on the stability of romantic relationships. If you're a maximiser, then even if you're partnered up you're always looking over your shoulder to see if there's a better alternative. The result is that your relationship is fragile and easily broken, rather than being committed."

The excessive choice we enjoy in our consumer-driven society, the Schwartz thesis goes, overwhelms and paralyses many of us - and it is impacting on our lives in ways that are becoming intolerable. The demand from US college students for psychological services far outstrips demand, for example. Schwartz thinks this is linked to the questions they are asking themselves about their endless life-choices. So it seems that choice is a good servant but a bad master. Schwartz agrees, but he says the position isn't hopeless. We can learn to counteract the problems of choice, and the way to do it is actually very simple.

"It's a learnt skill, but you start by being grateful for what is good in the choice you make instead of focusing on what's disappointing. And it turns out that noticing what is good is something you can cultivate. Just having a notepad by your bed, where you write down the two or three things that happened that day that are good, turns out to have an incredible effect on people's wellbeing. First of all, you start doing it spontaneously: you start noticing what's good, you notice when it happens, you are more in the moment and it improves every other aspect of your life. You experience more positive emotion, you're more optimistic about the future. So you develop the habit of focusing on what's good in decisions, and eventually it supplants the habit of focusing on what's disappointing."

One can imagine Tony Blair's Strategy Unit meeting going something like this. All the Whitehall suits say: "We gave the people a choice of healthcare services, railways, electricity services, pension plans, education, etc - so why aren't they happy?" And the professor of social theory and social action replies: "Well, maybe the problem is that they're just spoilt for choice." Maybe he's on to something.

'The Paradox of Choice: Why More Is Less' will be published in June by Ecco/HarperCollins (£12.99). To buy a copy, telephone 01206 255777

Schwartz's shopping theory

Panic in the supermarket

* Shoppers who confront a display of 30 jams or varieties of gourmet chocolate are less likely to purchase any than when they encounter a display of six.

* Students given 30 topics from which to choose to write an extra-credit essay are less likely to write one than those given six. And if they do write one, it tends to be of lower quality.

* The majority of medical patients do not want the decision authority that the canons of medical ethics have thrust upon them. Responsibility for medical decisions looks better to people in prospect than in reality: 65 per cent of respondents say that if they were to get cancer, they would want to be in charge of treatment decisions, but among those who actually have cancer, only 12 per cent want that control and responsibility.

* The more funds that employers in the United States offer their employees in 401(k) retirement plans, the less likely the employees are to invest in any, even though, in many cases, failing to do so costs them employer-matching funds of up to several thousand dollars a year.

* When maximisers, as opposed to satisficers, go shopping for big items or small ones, they spend more time looking, have a harder time deciding, look around more at what others are buying, and are less satisfied with their purchases.

* Maximising university students in their final year send out more CVs, investigate more different fields, go to more job interviews, and get better, higher-paying jobs than satisficers. But they are less satisfied with the jobs, and are much more stressed, anxious, frustrated and unhappy with the process.

Too much choice...

* ...increases the burden of gathering information to make a wise decision.

* ...increases the likelihood that people will regret the decisions they make.

* ...increases the likelihood that people will anticipate regretting the decision they make, with the result that they can't make a decision at all.

* ...increases the feeling of missed opportunities, as people encounter the attractive features of one option after another that they are rejecting.

* ...increases expectations about how good the chosen option should be. Since assessments of the quality of a choice are almost always made relative to one's expectations, as expectations rise, actual choices have a rising standard to meet if they are to produce satisfaction.

* ...increases the chances that people will blame themselves when their choices fail to live up to expectations. After all, with so many options out there, there is really no excuse for a disappointing choice.