Social networking websites Facebook and Twitter have created a generation obsessed with themselves, having short attention spans and a child-like desire for constant feedback on their lives, says an Oxford scientist.
According to Baroness Greenfield, professor of pharmacology at Oxford University, the growth of internet 'friendships' as well as greater use of computer games could effectively 'rewire' the brain.
She says this can lead to reduced concentration, a need for instant gratification and poor non-verbal skills, such as the ability to make eye contact during conversations.
Repeated exposure to social networking sites leaves users with an 'identity crisis', the Daily Mail reported the scientist as saying.
Baroness Greenfield, former director of research body the Royal Institution, said: "What concerns me is the banality of so much that goes out on Twitter."
"Why should someone be interested in what someone else has had for breakfast? It reminds me of a small child (saying): "Look at me Mummy, I'm doing this", "Look at me Mummy, I'm doing that".
She said that some Facebook users feel the need to become 'mini celebrities' who are watched and admired by others on a daily basis. They do things that are 'Facebook worthy' because the only way they can define themselves is by "people knowing about them".
"It's almost as if people are living in a world that's not a real world, but a world where what counts is what people think of you or (if they) can click on you," she said.
"Think of the implications for society if people worry more about what other people think about them than what they think about themselves."