A generation of children risks growing up with obsessive personalities, poor self-control, short attention spans and little empathy because of an addiction to social networking websites such as Twitter, a leading neuroscientist has warned

How many times do you click on your email icon in a day? Or look at Facebook, or Twitter? And how many times when reading on the internet do you click on a link navigating away from the text that was the original object of your enquiry? The web, it seems, is like an electronic sweet shop, forever tempting us in different directions. But does this mental promiscuity, this tendency to flit around online, make us, well, thicker?

power of modern electronic media – the net, mobile telephones and video games – to capture the attention of the human mind, particularly the young mind, and then distract it has lately become a subject of concern. We are, say the worriers, losing the ability to apply ourselves properly to a single task, like reading a book in its entirety or mastering a piece of music on an instrument, with the result that our thinking is becoming shallower. Sir Tom Stoppard aired a version of this view last week when he warned that the printed page was in danger of being "swept away" on a tide of technology, with the moving image assuming ever-greater precedence in the lives of young people.

Facebook has admitted that there is almost nothing it can do to stop young users setting up profiles, with academic research suggesting that more than a third of UK 9-12 year olds now have their own page on the social network.