Calculating gender equity's universal benefits Do boys lose out when girls start to do better in math? Do girls' successes lead to a "boy crisis"? An important new study says the answer is a definitive no. When girls do better in society, both sexes benefit. Gender equity is good for everybody. And boys and girls are becoming more equal, globally, in math performance. The study by Jonathan M. Kane and Janet E. Mertz of the University of Wisconsin analyzed scores from more than half a million fourth- and eighth-graders from 86 countries. It found essentially no gender differences between girls and boys in math performance. The students came from Western and Asian democracies and developing countries, as well as Muslim countries notable for their sex-segregated classes. But the really surprising finding was that the more equal the societies were around gender, the better everybody did in math. As the researchers conclude, "gender equity and other sociocultural factors ... are the primary determinants of mathematics performance at all levels for both boys and girls." The news about girls' increasingly better performance in math has been trickling in for years. But the findings were often dismissed by those who claimed that boys were inherently better at math and science. One argument was that the countries studied were cherry-picked to find girls doing well and therefore the results were not representative. If you buy that argument, putting resources into improving girls' math and science abilities is a waste of time because you are going against "nature." As Ethan Siegel, a theoretical astrophysicist in Portland, Ore., notes on his blog, Starts With a Bang: "You know how prejudices and confirmation biases work: If you think things are a certain way for a certain reason, then when your reasoning is shown to be incorrect because your premise is flawed, what do you do? Do you question your conclusions, or do you just find a new explanation that brings you to that same conclusion? Most recently, the argument goes something like, 'Even though men and women are equal on average in math ability, men have a greater variance in their abilities. So there are more very dumb men, but also more very smart men, and those are the ones who become scientists, etc.' In fact, based on this reasoning, some people claim that only males can be superstars in the all-important and highly lucrative STEM fields (science, technology, engineering and mathematics). But if this "variance " argument were true, you'd find boys at the higher end of the distribution across all countries because we're talking genes here. Kane and Mertz found no evidence to support that claim. In some countries, as predicted, boys' variance was higher than girls'. In other countries, there were no differences, and in yet others, girls' scores showed more variance than boys. The new study has data from more countries than previous studies, and from all types of cultures. The width and breadth of this study and its findings should end, forever, the claim that boys are naturally hard-wired for math and girls are not. And it should ease the fears of those who think that when women and girls make gains, males automatically lose. Mertz says: "Many folks believe gender equity is a win-lose, zero-sum game: If females are given more, males end up with less. Our results indicate that, at least for math achievement, gender equity is a win-win situation. So it's time to call a halt to the endless search for a male math gene, to the cry for more and more studies because someday we're going to find proof of men's innate superiority, and to the ongoing spate of articles saying that we really know that nature makes boys better. It's time to move from bickering over data to building new evidence-based public policies that will empower all of our children - and, in turn, society. Rosalind C. Barnett, senior scientist at the Brandeis Women's Studies Research Center, and Boston University journalism professor Caryl Rivers are the coauthors of "The Truth About Girls and Boys: Challenging Toxic Stereotypes About Our Children."