Charles is 13. Until two months ago he was hooked on his home computer, playing mindless games for up to 30 hours a week. He's typical of an increasing number of children with a new problem - computer dependency. Like most parents, Charles's mum and dad thought a computer would help him educationally and at first they encouraged him to become computer 'literate'. Now, alarming research indicates that some children, particularly boys, become so entranced with the machine that their psychological and emotional development is affected. They learn to prefer computers to people.