When given the same opportunities and encouragement as boys, girls are just as good at high level math as their male peers, a new study finds. This contradicts other findings that girls are as capable at math on average, but can’t excel the way males can. It’s also a rebuttal to former Harvard University president Larry Summers, researchers said, who claimed in 2005 that biological differences might be a reason fewer women become math professors (Summers now chairs U.S President Barack Obama’s Council of Economic Advisers). “We conclude that gender inequality, not lack of innate ability or ‘intrinsic aptitude’, is the primary reason fewer females than males are identified as excelling in mathematics performance in most countries, including the United States,” Janet Hyde and Janet Mertz of the University of Wisconsin in Madison wrote in the study, which was published in the Proceedings of the National Academy of Sciences. In it, they did a statistical analysis comparing math scores and contests with the World Economic Forum’s 2007 Gender Gap Index, which ranks countries according to employment, economic and political opportunities, education and medical status. “Countries with greater gender equity are also the ones where the ratio of girls to boys doing well in math is close to equal,” Mertz told Reuters.