The biggest change: he divided the classes by gender. Because males have less serotonin in their brains, which Gray was taught may cause them to fidget more, desks were removed from the boys' classrooms and they got short exercise periods throughout the day. Because females have more oxytocin, a hormone linked to bonding, girls were given a carpeted area where they sit and discuss their feelings. Because boys have higher levels of testosterone and are theoretically more competitive, they were given timed, multiple-choice tests. The girls were given multiple-choice tests, too, but got more time to complete them. Gray says the gender-based curriculum gave the school "the edge we needed." Tests scores are up. Discipline problems are down. This year the fifth and sixth grades at Foust are adopting the new curriculum, too.