Shopping centres use plenty of tricks to make you take out your wallet. One of the men who helps them do it is Paco Underhill. He tells Melanie Morris about the techniques they use

Paco Underhill makes his living wandering around shops and shopping malls. As a retail anthropologist he observes the hows and whys that get shoppers to part with their money.

Underhill, who is American, describes himself as a professional browser, "an ill-put-together man, seen as a guru, who loves going to stores as an exercise in voyeurism". He's been doing it for 20-plus years through his company, Envirosell, "a testing agency for merchants and markets". He's worked with blue-chip names from Adidas to Starbucks and from Disney to McDonald's. In Underhill's world nothing happens by accident. Getting people to empty their wallets is an art form - and the result of carefully thought-out operations.

This is the man who identified the concept of "butt brushing": having one's personal space invaded by other shoppers when a shop's aisles are too narrow to cater for a woman's hunched frame. It's not a good thing, so Underhill told his client to make the aisles wider. Profits climbed instantly.

Underhill can not only tell you that men and women shop differently - no big surprise - but also tell you why. "Take the changing room, for example. If a man goes in there and the item fits it's usually bought. In a woman's case this may not necessarily happen. The act of trying on clothes is part of the whole buzz of shopping therapy." It's pretty obvious, perhaps, but the multinationals seem to need Underhill to tell them, and they pay handsomely for the privilege.

Who could be more suited than him to write a book on shopping-mall culture? (Pronounce it "mawl" and it becomes a globally recognised word, like taxi, Coke and Nike.) He has already had phenomenal success with his first foray into publishing. Why We Buy: The Science Of Shopping is a worldwide best-seller that has been translated into more than 20 languages and, five years on, still sells 100,000 copies a year in the US.

His new book, The Call Of The Mall: A Walking Tour Through The Shopping Mall, will no doubt follow suit, appealing to marketeers, academics, professionals and enthusiastic shoppers alike. It's one of those books, like Fast Food Nation, that works beyond its niche. Because, like our insatiable appetite for burgers, Baywatch and The Simpsons, nearly everyone loves to crawl around a "mawl" once in a while.

The Call Of The Mall is smart. It's one of those books you find yourself silently nodding along to. Yes, he's right, shopping malls never look like much from the outside, and that's because nobody ever lingers farther than a few feet from the doorway. And, yes, malls are today's version of yesteryear's marketplace, where people go to hang out and chat as well as buy chattels. And, yes, that's right too: the bathrooms in modern shopping malls are always clean, but they're "plain Jane vanilla" in their design.

Underhill knows. In the past couple of decades he has visited more than 300 malls around the world. He's studied every detail about them: why lingerie shops don't have waiting areas for men; the missing item from every food court; the verdant-but-dull qualities of mall planting. And he knows the answers: because women need time to themselves when shopping for underwear (it's part of the fantasy), apples and because, beyond looking green, it doesn't matter what it is.

Underhill identifies different types of mall visitors and why they attend. He's hilarious about mall walkers, the velure-clad pensioners who were initially welcomed with a diet of freebies, vouchers and other promotions before the tenants got tired of their grumpy old ways. He's canny about why community groups - scouts, martial artists and children's choirs - are welcome to perform in their local malls: because they bring proud parents and their wallets in their wake.

He fails, however, to refer to Tommy Tiernan's "Fanta-filled f***ers", the uncontrollable, sugar-crazed kids who screech around their parents' ankles, making everyone's lives hell. But maybe they're an Irish phenomenon.

So what, in Underhill's mind, would make a good mall great? "It would be one that starts with the construction of bathrooms, car parks and sitting areas first and then has the shops built around them. Right now shopping malls are created from spreadsheets, leasing agents and lawyers. But what about people's needs? They must come higher on the priority list.

"At the moment I think most malls are interfacing with the woman of 20 years ago. Then she was a housewife with small kids. In 2004 60 to 70 per cent of women over 20 work outside the home. She might also be a wife, a mother and a wage slave. There's a challenge to mall owners to address the needs of this very different woman, and it's enormous.

"And women, as we know, buy differently to men, so there are further challenges that retail staff must be aware of. Men will buy a drill; women will choose something to put up pictures. It's not the power under the engine they're are interested in, it's the nature of the output."

The Call Of The Mall sees Underhill come up with a host of theories and a few solutions as to how mall culture could improve. "In the future, if malls don't update and redefine themselves, they're toast. I can already see a return to shopping- centre culture, with smaller clusters of specialist stores that appeal to particular segments of the community. I also see a change in the tenant mix, a return to more exciting, local merchants rather than the big chains selling 'unique and fun' products. I think there'll also be an increase in services at the mall, like banks, laundromats and travel agents. Some supermarkets in the US are already setting up field stores in the car parks, selling seasonal essentials like deckchairs, charcoal briquettes and suntan lotion in the summer. This means you can just pull up and get what you need without having to have the full shopping experience. I think this is a good idea and one that will spread."

It all sounds very functional, but as Underhill points out malls are also about fantasy, about heading out for the day and, perhaps, coming home with nothing but having had a great experience in the process. So where are his favourites? "For luxury goods you can't beat South Coast Plaza in Orange County, Los Angeles. There's more Botox, collagen and uplift bras per square foot there than anywhere else I've been. If it's entertainment you're after rather than shopping, there's a mall in Edmonton [in Canada\] that's second to none, with climbing walls, Imax theatres and more. The best retail therapy can be found in the Mega Mall, outside Moscow, which has IKEA as one anchor tenant as well as an amazing supermarket and coat-check facilities. I particularly love the food court there: it's great, with every sort of ethnic cuisine from the former Soviet Union.

"Finally, for families, I think the Diagano in Barcelona is really well designed. It's part of a larger urban-renewal programme and is really well integrated into the community. On a practical level there's a super supermarket and it's easy for baby strollers."

Other malls of distinction include Bal Harbour Shops, in Florida, where Cartier, Louis Vuitton and Chopard sit along side each other just as Boots, Warner Bros and Eason do at Liffey Valley, in Dublin. The indoor funfair at MetroCentre, near Newcastle in England, is a sight to rival Funderland, even if the wall-mounted defibrillators might give second thoughts to shoppers contemplating boarding the big dipper. And those who like the designer looks of malls in Dubai, Hong Kong and Toronto will love Terence Conran's Ocean Terminal, on Edinburgh's waterfront. Just remember where you parked the car.

• The Call Of The Mall: A Walking Tour Through The Shopping Mall by Paco Underhill is published by Profile Business, £15 in UK

A retail anthropologist's view of the world

According to Paco Underhill, right:

• You're not ready to make buying decisions for the first 10 or 15 feet of a mall. That's how long it takes to acclimatise and is why you'll find banks, hairdressers and the like immediately inside the door.

• Men are more interested in the social aspect of shopping

than they are in the retail part; women see shopping as coming first.

• The only females who love the other aspects of a mall are teenage girls, possibly because it is the only non-home, non-school environment they have. But they outgrow that by the time they're at college. From then on they're at malls to shop.

• The higher-end a store, the more different it will look from the mall that surrounds it.

• When it comes to remembering where you parked your car, men like car parks to be divided by numbers and letters, women prefer colours and children go for symbols and pictures.

• In the US some malls, such as Wal-Mart, permit overnight parking. Visitors arrive in camper vans, then use bathroom facilities and the food court before going shopping.