20191115 女生学数学更难吗？

MARY LOUISE KELLY, HOST:

Math is a field that is dominated by men, yet young boys and girls seem to be no different in math ability. NPR's Jon Hamilton reports on a new study comparing the brain activity of boys and girls doing basic math.

JON HAMILTON, BYLINE: In high school, boys are about twice as likely as girls to get top scores on standardized math tests. But Jessica Cantlon of Carnegie Mellon University says that doesn't mean male brains have an inherent advantage.

JESSICA CANTLON: When we're seeing differences in adult brains or behavior, we don't necessarily know the history of how those differences came about.

HAMILTON: It could be nurture or nature. To learn more, Cantlon and a team of scientists studied brain activity patterns in more than 100 children. Their ages ranged from 3 to 10. And Cantlon says the kids spent up to half an hour in the noisy confines of a magnetic resonance scanner.

CANTLON: We had boys and girls watch educational videos about mathematics while they were being scanned.

HAMILTON: Including this clip from "Sesame Street."

(SOUNDBITE OF TV SHOW, "SESAME STREET")

UNIDENTIFIED ACTORS: (As Counting Crows, singing) One and two and three, counting is our favorite thing.

HAMILTON: Then, Cantlon says, the team looked to see which brain networks became active during math tasks.

CANTLON: If you define the mathematics network in girls and you define the mathematics network in boys, they're indistinguishable.

HAMILTON: Cantlon suspects that the math gender gap reflects societal messages more than biology. She also says that even though more women are entering math and science these days, it can still be daunting to choose a field dominated by men.

CANTLON: You can look even now at ratios of women and men participating in different activities, and you can get the hint.

HAMILTON: Cantlon says her study doesn't rule out the possibility that male brains acquire a math advantage during adolescence.

CANTLON: What we're showing here is, at least very early in development, they don't start out that way.

HAMILTON: The brain activity study appears in the journal Science of Learning. And David Geary of the University of Missouri says the results aren't terribly surprising.

DAVID GEARY: Because typically, we don't see sex differences at the ages assessed in this study or for the types of math tasks that they did, which were fairly simple.

HAMILTON: Geary says differences seem to show up later and involve very high-level math tasks. His own research has found that in most countries, female students perform just as well as male students in science-related subjects. Yet paradoxically, Geary says, females are less likely to get degrees in fields like math and computer science if they live in wealthier countries with greater gender equality.

GEARY: As things get better in a country, people follow their interests more, and they go with their academic strengths and worry a little bit less about how much money they're going to make.

HAMILTON: Geary says the most obvious gender gap in education worldwide doesn't involve math or science. It's reading and writing abilities where boys lag well behind girls.

Erin Fahle of St. John's University was part of a study that found something similar in the U.S.

ERIN FAHLE: Across the entire United States, there's not really a gender achievement gap in math, but there is a gender achievement gap in reading.

HAMILTON: Fahle says the exception is affluent areas, where boys are closer to girls in reading ability and have an edge when it comes to math. Fahle says that suggests that girls in some areas are constrained by stereotypes around gender. But, she says, so are boys.

FAHLE: And that's reflected in the fact that essentially every U.S. school district, boys are scoring lower, on average, than girls in reading and language arts.

HAMILTON: Which may help explain why boys often choose math and science.