SEVERAL researchers have shown that adults who played games in the nursery are more likely to be happily married and vote in elections than those who followed a narrow, academic pre-school curriculum. But now a study of more than 120 children has discovered that those taught formal academic skills at nursery howed more anxiety and lower self-esteem by the time they reached primary, Professor Kathy Sylva, of Oxford University, told the North of England Conference this week. She said children encouraged to initiate their own play were better at reading and writing by the time they reached primary school.