There is plenty of evidence that, at least in the US, that simply thinking "black people don't do well on this test" or "women aren't good at math" lowers the t

There is plenty of evidence that, at least in the US, that simply thinking "black people don't do well on this test" or "women aren't good at math" lowers the test scores of both black people and women. Since these are both "common knowledge," that is a very good reason to exclude those tests. This is called "stereotype threat". The good news is that there's also emerging research showing how test scores for blacks & women can be raised by exposing them to certain facts/examples that reduce the effect of "stereotype threat".