In Toys'R'Us you see the hard truth of the playground

This Toys'R'Us store looks, at first glance, like a big white temple dedicated to novelty. CD-Roms of bosomy Lara Croft (£34.99 for Tomb Raider 3), ready to slot into your Family Multimedia Centre ("only £999, including VAT"). The flashiest of the new yo-yos (Yomega, £19.99). Teletubbies skates. A slender book called The Totally 100 Per Cent Unofficial Leonardo di Caprio Special.

But first glances deceive. Children are very conservative. Next to di Caprio are The Wombles Official Annual 1999, Bunty for Girls 1999, even the Rupert Annual. The videos shelf showcases Postman Pat, Roald Dahl, Enid Blyton. Lego has a rival called K'Nex, but the K'Nex display is swamped by Lego Pre-School, Lego Basic, Lego System and Lego Technic.

There is My Little Talking Computer, but there is still also My Little Pony. There is an electronic learning section (education, once a turn-off, is a big new sales gimmick for toys), but the star of Counting Carrots is old Winnie the Pooh: "Carrots light up to teach counting!" This, marked at £29.87, is an exception to the rule that all prices must end in nine. A useful lesson in itself.

In 1965 the British Association of Toy Retailers started listing a top toy of the year. (This year it is an electronic gremlin called Furby; two makes of yo-yo come joint second.) A generation later, only four of these champions have died out. Toy shops still stock the rest. Even the Rubik's cube sells well. The Mastermind board game was invented before the television show - otherwise there would have been copyright trouble - and has outlasted it. Monopoly, Scrabble, Ludo, are all stacked by the Toys'R'Us front door.

These are board games where the rules can be learnt as you go along. They don't require hours of preliminary explanation. In this, they are like the street and playground games chronicled by Iona and Peter Opie in their epic series of studies. If children had to stop to work out every elaborate detail beforehand, the Opies noted, the game would never start.

Few toys or games are now made by British manufacturers. Mattel (best known for Barbie) owns Matchbox and Spears; Hasbro (Action Man) owns Waddington and part-owns K'Nex. Both are American. Lego is Danish. Meccano is made in France, skates in China. Toys are a teeny version of the incompetence of British industry. I wonder if a Scalextric model of the economy would sell. If only to Gordon Brown?

The secretary of the toy sellers' association worries that, with all the takeovers, he may soon only need six tables for the annual dinner: three for manufacturers and three for stores. Toys'R'Us came over from America in 1985. It now has 61 stores. In Britain it comes third behind Woolworths and Argos. The Argos catalogue is the price setter.

Here in Southwark, the big white shed is opposite a Jet petrol station, and just down the road from B&Q, Carpetland, KwikFit and Tesco. Toys'R'Us is one of the wave of American retail inventions - McDonald's, Howard Johnson, Pizza Hut - which rode to prosperity on the interstate highway system. Wherever you were, you always knew you would get the same thing. Toys'R'Us is 50 years old this year. It has stores in 28 countries, and is probably the world's biggest toy seller. It is a very secretive firm but, through gritted teeth, it has just had to announce a third-quarter loss of $475 million. The trouble seems to be cut-price competition in its American home base.

In one sense, almost everything sold at Toys'R'Us is an irrelevance. The Opies argued how important it was for children to play games where they policed the rules themselves. Street games have no umpire. Games with formal rules, laid down by adults, don't have the same value. (Lego, being rule-less, sneaks past this reproof.)

It is always said that Opie-type games have died out. But adult eyes grow blind. Unarguably, however, fewer children play games on their way to and from school. They are loaded into cars. In Children's Games with Things, published last year, Iona Opie said that - perhaps for this reason - the "venerable and ingenious" game of whips and tops had died out. (I can't see it at Toys'R'Us).

Yet where there's memory, there's hope. She writes about marbles, hopscotch, skipping. But she has no entry for the yo-yo. It was a dead fad from the 1930s. The yo-yo is now alive and whizzing.

Standing and watching playgrounds, she observed that young children were strict about traditional demarcations. Girls did girls' things, and boys did boys' things. This afternoon I walk down the aisles of Action Man (khaki) and Barbie (dazzling pink). Boys are asking for Action Man, girls for Barbie.

Southwark is a "multicultural" borough. The road to Toys'R'Us is lined with African pentecostal churches. There are Jamaican and African cafes and clubs. The lorry park next to Tesco is on Mandela Way. In Toys'R'Us, several of the dolls come in white and black alternatives.

But I have to report that I saw no black parent, and no black child, buying anything other than a white doll. This may be the hard, conservative truth of the playground.