A standard component of both racism and sexism is that the other sex and other races are inferior in IQ (whatever that means) to one’s own race and gender. Througout history, various scientific and pseudoscientific theories have been advanced in order to defend such alleged differences. Because of this, the study of IQ in the context of race and gender has often been subject to harsh criticism. After all, it might be suspected that anyone intested in such matters intends to employ their results in the service of racism or sexism.
While this concern does have some merit, it would be unfortunate and unscientific to simply close off these branches of research because they might be considered racist or sexist.
Interestingly, such research might actually help to undercut racism and sexism. For example, the usual line is that a gender or race is somehow inherently (often genetically) inferior to another and hence this explains the disparity in IQ testing. If this were true, then the scores on IQ tests should remain more or less constant-unless, of course, the gender or race in question happened to be genetically altered.
Recent research in IQ tests has shown that the test results have changed over the years. For example, the gap between whites and blacks on IQ tests has narrow by 25% over thirty years. Obviously, if IQ disparity was based on race, then this sort of change should not occur. If IQ disparity is based on other factors (like access to education), then such a change is easy to explain.