Two groups of women are asked to write a math test.

One group is supported by a positive atmosphere.

The other is told the test will determine whether they are “smart in math,” conjuring up the stereotype that — when it comes to math — men are smarter than women.

As expected, the stereotyped group did worse than the supported one.

But the University of Toronto psychology researchers went further. They asked both groups to perform a series of tasks afterwards designed to gauge aggression levels, ability to focus and powers of self-discipline.

One task involved sampling three different flavours of ice cream, each flavour piled three scoops high.

“In these follow-up tests, the women who felt discriminated against ate more than their peers in the control group,” reports assistant psychology Prof. Michael Inzlicht at University of Toronto’s Scarborough campus, who led the research.

“They showed more hostility than the control group and they performed more poorly on tests that measured their cognitive skills.”

The results, to be published in the next Journal of Personality and Social Psychology, suggest stereotyping and prejudice can negatively affect a person after the act of prejudice is over, and in indirect ways.