School students are still being held back by their own “gender perceptions”, according to an international study by the Organisation for Economic Co-operation and Development. It found that, in most countries, girls and boys showed similar results in the Programme for International Student Assessment, which tests 15-year-olds. But traditional preferences emerge from systematic assessment of gender differences which show girls doing better in reading, boys ahead in maths in most countries and both sexes performing equally well in science (although boys are in the lead in six countries, including the UK).