Madeleine Finlay sits down with her co-host and Guardian science editor, Ian Sample, to discuss three science stories from the week, including a study that offers a clue in the age-old debate about whether sex differences are present from birth or a product of socialisation. Also on the agenda is the super El Niño, which is predicted to lead to 450,000 deaths in the next six months, and an answer to why the UK’s meningitis outbreak earlier this year was so big.