Friday, October 20, 2006

Women's Math Scores Affected by Suggestion

Telling women they cannot do well in math may turn out to be a self-fulfilling statement.

In tests in Canada, women who were told that men and women do math equally well did much better than those who were told there is a genetic difference in math ability.

And women who heard there were differences caused by environment -- such as math teachers giving more attention to boys -- outperformed those who were simply reminded they were female.

The women who did better in the tests got nearly twice as many right answers as those in the other groups, said Steven J. Heine, a psychology professor at the University of British Columbia in Vancouver.

"The findings suggest that people tend to accept genetic explanations as if they're more powerful or irrevocable, which can lead to self-fulfilling prophecies," Heine said.

Heine and doctoral student Ilan Dar-Nimrod divided more than 220 women into four groups and administered math, along with reading, comprehension tests conveying different messages about women's math aptitudes. Their findings are in today's issue of Science.

Algae Causing Jump In Ocean 'Dead Zones'

Scientists have found 200 "dead zones" in the world's oceans, a 34 percent jump from two years ago, a U.N. report yesterday showed.

Pollution-fed algae, which deprives other living marine life of oxygen, are the cause of most of the dead zones, areas often tens of thousands of square miles in size. Scientists chiefly blame fertilizer and other farm runoff, sewage, and the burning of fossil fuels.

Those contain an excess of nutrients, particularly phosphorous and nitrogen, that cause explosive blooms of tiny plants known as phytoplankton. When they die, they sink to the bottom, where they are eaten by bacteria that use up the oxygen in the water.

Antarctic Ozone Hole Is Largest Measured

This year's Antarctic ozone hole is the biggest ever, government scientists said yesterday.

The so-called hole is a region where there is severe depletion of the layer of ozone -- a form of oxygen -- in the upper atmosphere that protects life on Earth by blocking the sun's ultraviolet rays.

Scientists say human-produced gases containing bromine and chlorine damage the layer, causing the hole. That is why many compounds such as spray-can propellants have been banned in recent years.

"From September 21 to 30, the average area of the ozone hole was the largest ever observed, at 10.6 million square miles," said Paul Newman, atmospheric scientist at NASA's Goddard Space Flight Center in Greenbelt. That's larger than the area of North America.

-- From News Services

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