Facebook and Twitter have created a generation obsessed with themselves, who have short attention spans and a childlike desire for constant feedback on their lives, a top scientist believes. Baroness Greenfield, professor of pharmacology at Oxford University, believes the growth of internet 'friendships' could effectively 'rewire' the brain. This can result in reduced concentration, a need for instant gratification and poor non-verbal skills, such as the ability to make eye contact during conversations. 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...