The theory that there is one, over-all general kind of intelligence is not scientifically demonstrable; the profusion of intelligence testing and the assignment to an individual for most of his or her student life of an arbitrary intelligence quotient rating may be an infringement of civil liberties. Such ratings may be used to unfairly screen out students for educational programmes, or applicants for job or promotional opportunities. The tests themselves are often biased towards privileged backgrounds and the dominant ethnic culture. Thus gifted but disadvantaged individuals' scores will not reflect their capabilities.