Women exposed to bogus scientific theories linking their gender to poor math skills did worse on arithmetic tests than others, according to a study that suggests even false stereotypes about genetic makeup can sway performance.

The three-year study at the University of British Columbia involved 135 women taking challenging math tests similar to those used for graduate school entrance exams.

Before they were given the test, the women were required to read one of four essays — three of them dealing with gender difference in math. One essay argued there was no difference, a second argued the difference was genetic and a third said the difference was the result of social construction and the way girls were taught in elementary school. The fourth essay covered the subject of women in art.

Research has shown that simply reminding a person that he or she falls into some stereotyped category can change the person's performance, in what is known as a stereotype threat.

When the women were told bogus scientific theories about being born bad at math, they did worse, says the study, which was published Thursday in the journal Science.

The women who were told that prior experience determined their math ability got twice as many answers right on the exam as women who were told their genetics were to blame, the researchers said.

"So, when they hear there's a gene for math, and they might not have it, they can be affected," said Ilan Dar-Nimrod, a doctoral student in social psychology and the lead author of the study, Exposure to Scientific Theories Affects Women's Math Performance.

Most people see genes as fate

Dar-Nimrod said the latest study shows genetics-based theories — even if they're bogus — can be powerful.

"And I think that's what the study shows," he told the CBC on Thursday. "They are much more affected than if they hear that people from their own neighbourhood, or people who went to their school are not good in math."

Steven Heine, an associate professor of social psychology at UBC and the co-author of the study, said the study should force researchers and the media to be more cautious when talking about a "gene" for obesity or other diseases because most people incorrectly see genes as fate.

"People seem to interpret it as meaning that if I have this gene I must become obese," he said.

"The relations between genes and behaviour are very complex and unfortunately people do view them in more deterministic terms than they ought to."

With files from the Canadian Press