It is said to occur when institutional policies and practices unintentionally discriminate against women and certain ethnic groups. This concept is called upon in individual cases where no intentional discrimination is demonstrated and is applied to whole institutions on the basis of statistics for the faculty and student populations. The doctrine obviates the need to examine historical, sociological, psychological and other factors that might account for representation patterns. In universities the doctrine opens the door for unsustainable policies such as preferential treatment of special interest groups and assaults the principle of merit in education and scholarship. Moreover, by absolving its proponents from the responsibility of actually identifying a discrimination mechanism, it legitimates both shoddy arguments and witch-hunts for racism and sexism in every aspect of human behaviour.
Unintentional discrimination can, of course, occur in educational institutions and workplaces.
It can be rectified when the source of bias is identified. Two examples are the provision of facilities enabling the disabled to attend colleges and universities and of left-handed writing tablet chairs in lecture halls. Thus the possibility of such discrimination cannot be dismissed, but the emphasis must be upon identifying a bias mechanism so that appropriate adjustments can be made. This rational understanding of systemic discrimination, however, seems not to have gained acceptance because the proportionality fallacy is now deeply entrenched. As an example, U.S. aptitude tests for screening students are sometimes arbitrarily adjusted to obtain strict proportionality by race and sex.