MySpace and Facebook sites have created a fashion for collecting friends instead of stamps or coins, the conference was told. Users compete with one another to rack up more online friends than anyone else, listing them in the same way that they might show off a new car or the latest gadget.

Similarly, there is competition to be able to boast the highest number and the most impressive “trophy friends” — celebrities such as Lily Allen who use MySpace and other sites.

The practice of collecting friends, dubbed “MySpace whoring”, is part of a social revolution that is “changing the nature of human relationships”, the conference was told. Whereas relationships traditionally started with a face-to-face meeting, fans of social networking sites can make new contacts at the click of a mouse.

Will Reader, of Sheffield Hallam University, told the association that the virtual world had enabled people to make many more friends than they would in the three-dimensional world. Users of the social networking sites say that one in ten of their close friends has been made in the virtual domain.

Most people have about five close friends and know about 150 people in total, most of them acquaintances with whom they are on nodding terms.Cyber-users have the same number of close friends but many more casual acquaintances. Dr Reader was speaking yesterday about the initial findings into a study of how MySpace and Facebook are changing relationships.

He said that the biggest impact was being experienced in the number of “casual relationships on virtual nodding terms”. Sitting at a computer was no longer a solitary act: the computer could be a social hub bringing people together from all over the world.

“The web was solitary. This is bringing back the social side of human interaction.” But, he said, this had been carried to an extreme by many users who went by quantity rather than quality and had become the trainspotters of the virtual world.

“To have in excess of 1,000 friends is not uncommon,” he said. “It can be a bit like trainspotting. They just want to get as many people on to their list as possible.

“It does upset some people. They start by feeling good that they appear to have made a new friend only to find out that they are simply being added to a list. They’re not wanted for themselves; they’re wanted to extend a list.”

This and the nature of online friendship had spawned “the phenomenon of defriending” as a means of severing relationships. Instead of having a row or pointedly refusing to speak to a friend whose views or behaviour were unacceptable, they could simply have their names taken off a list of friends.

Dr Reader said that it added a dynamic to the end of friendship: “Normally a friendship will fade out. You gradually lose contact. On these sites you remove them. It’s a type of spring clean and the other person knows they’ve been removed.”

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