As shown in recent studies, cognitive ability tests, or simply known as IQ tests represent the best single predictor of job performance, but also represent the predictor most likely to have substantial adverse impact on employment opportunities for members of several racial and ethnic minority groups. Debates over the use of these tests in selection often involve trade-offs between two criteria that are valued by decision makers--that is, efficiency and equity. Findings and methods from decision research can help us frame these trade-offs, but in most cases they cannot be avoided.
Protesters of IQ tests use evidences such as difference in performance of black and other groups on those tests. Statistics shows that black score 10-15% lower than the average of other races. However, supporters of IQ tests pointed out that the reason is not among race, but come mainly from education level and social segregation. In the past few years, standards were set for non-discriminative intelligence test as "tests need to be culturally fair and items do not favor a particular cultural group".
To make an intelligence test fair, let's first compare the following two video clips. The first one shows a test given orally to three different people with different backgrounds. The first person is a regular highs school student, second one is a lower social class citizen and the third is an immigrant from Iran with a university degree. The test demands background information to specific English words, and thus is biased as foreign students whose native language is not English will have less chances to know the meanings. However, in the second, the test was given in forms of figures and numbers. If a written instruction is also given in the language of the test taker, it will eliminate bias of culture.