Is it true that humans use just 10% of their brains? It\xe2\u20ac\u2122s the premise of the new film Lucy, in which the brain capacity of Scarlett Johansson\xe2\u20ac\u2122s character increases to dangerous levels. Tim Harford uses considerably more than 10% of his brain to separate the neuro-science facts from the fiction with Professor Sophie Scott. \nWhat drives the price of footballers? Tim Harford tries to understand the huge transfer fees with Raffaele Poli from the CIES Football Observatory and football agent Seb Ewen. \nPresenter: Tim Harford \nProducer: Ruth Alexander\nThis programme was first broadcast on the BBC World Service.