To discriminate is to make a distinction. There are several meanings of the word, including statistical discrimination, or the actions of a circuit called a discriminator. This article addresses the most common colloquial sense of the word, invidious discrimination. That is, irrational social, racial, religious, sexual, ethnic and age-related discrimination of people.

Definition

Invidious discrimination involves formally or informally classifying people into different groups and according the members of each group distinct, and typically unequal, treatments, rights and obligations without a rational justification for the different treatment. If there is rational justification for the different treatment, then the discrimination is not invidious. The criteria delineating the groups, such as gender, race, or class, determine the kind of discrimination.

Invidious discrimination generally refers to treating one group of people less well than another on such grounds as their race (racism), gender (sexism), religion (religious discrimination), ethnic background, nationality, disability, sexual orientation, preference or behavior, results of IQ testing, age (ageism) or political views. Discrimination on the basis of such grounds as subcultural preference (Punks, Hippies, Mods vs. Rockers) is also common. In 2003, Robert W. Fuller coined the term rankism in his book Somebodies and Nobodies: Overcoming the Abuse of Rank to describe negative discrimination predicated on rank difference between individuals (for example, a customer humiliating a waitress or a boss picking on an employee).

The effects of invidious discrimination span the spectrum from mild, such as slow or unhelpful retail service, through racial and ethnic slurs, denial of employment or housing, to hate crimes and genocide.

Use of the term carries the implication that the factors on which the invidious discrimination is based are intrinsically irrelevant to the decision being influenced. Generally, the aggrieved group is considered by the discriminator as inferior to others.

Institutionalized discrimination and responses

Many governments have attempted to control discrimination through civil rights legislation, equal opportunity laws and institutionalised policies of affirmative action (called reverse discrimination by its opponents).

Some governments have formalized and supported discrimination. Examples include apartheid in South Africa, institutionalized racial segregation in the USA from the Civil War through the 1960s, the "Jewish problem" in Nazi Germany, and re-education camps in some communist countries.

Even in western, secular countries, governments practice discrimination. For example, governments may provide better treatment to citizens than to non-citizens. Unemployed citizens may receive welfare benefits funded by taxpayers, while unemployed non-citizens may be denied such benefits. Governments often have the power to forcefully expel non-citizens but cannot expel citizens. Discrimination based on citizenship status is not generally considered illegal.

Religious Discrimination

Religious intolerance often manifests itself in discriminatory behaviours. During the Middle Ages, in the Crusades, Popes, kings, and emperors tried to draw on Christian unity to defend their lands from some followers of Islam, which was spreading along Europe's southern and eastern borders. Roman Catholic countries have historically persecuted dissenters, for example with the Spanish Inquisition. Rulers of Protestant countries sponsored discrimination against members of the Roman Catholic faith. During Tudor and Stuart times, rulers of the United Kingdom persecuted both Catholics and non-Catholics at intervals for political reasons. Non-Muslims are discriminated against under many Islamic theocratic states. Jews and Christians have historically had fewer rights than Muslim citizens under Muslim states; non-Muslim monotheists have been consigned to the status of dhimmis in some cases. Marxist states have discriminated against all religions at some time or another.

For example, the Kingdom of Jordan forbids Jews from becoming citizens, although peoples of any other group are allowed to do so (law No. 6, sect. 3, of April 3, 1954; restated in law no. 7, sect. 2, of April 1, 1963). Saudi Arabia forbids non-Muslims from practising their religion in public, and clergy may not enter the country to lead ceremonies of other faiths. Christians asking Muslims to convert to Christianity have been persecuted and arrested; Muslims who have converted to Christianity have been executed as apostates. Fictional tales of Jews committing diabolic crimes are published by the state. The article on discrimination against non-Muslims in Saudi Arabia discuses this subject in more depth.

According to reports from the U.S. Department of State, non-Muslims also suffer discrimination in many non-Arab Muslim nations. Separate articles discuss discrimination against non-Muslims in Afghanistan, Iran, Malaysia, Mauritania, Pakistan and Sudan.

The State of Israel is often accused of discrimination against Palestinians; this topic is discussed in the article on apartheid.

Some New religious movements often claim that they are discriminated for their non-conformist beliefs. They claim apostates of these movements are the ones carrying the discrimination.

Ageism

Ageism is discrimination against a person or group on the grounds of age. Although theoretically the word can refer to the discrimination against any age group, ageism usually comes in one of two forms: discrimination against youth, and discrimination against the elderly.

Some underage teenagers consider that they're victims of ageism—prejudice on the grounds of age—and that they should be treated more respectfully by adults and not as second-class citizens. Some complain that social stratification in age groups causes outsiders to incorrectly stereotype and generalize the group, for instance that all adolescents are equally immature, violent or rebellious. Some have organized groups against ageism.

The Paradox of Discrimination

Many people assume that when there is discrimination, one group of people is given more favorable treatment than others. This is not always the case. It is possible to have cases where it is not at all clear which group is given the more favorable treatment.

• Example: A country is under attack during wartime. The war is so ferocious that 80% of the combatants are killed. A law has been passed to forcefully conscript males between 18-24 years of age into the frontline, but females are forbidden to participate.
• Question: Who is suffering unfair discrimination?

There are four possible answers:

1. Males are suffering unfair discrimination. They are forced to participate in the effort which will result in a high probability of death.
2. Females are suffering unfair discrimination. They are prevented from participation in the war effort to protect their homeland.
3. Both males and females are suffering unfair discrimination.
4. No one suffers unfair discrimination. The ruling was made because of valid intrinsic reasons suiting men and women to different activities. (This is not to assert anything about the relative suitability of men and women for conflict.) There may however be other examples of a situation some might regard as discriminatory, but in which there was no discrimination because of the decision was based on the intrinsic suitedness of the two groups to the roles being apportioned. An example might be symphony orchestras made up of all-white musicians selected by blind auditions. In a blind audition, the musician plays behind a curtain. The reviewer can't see the player, so there is no possibility of skin or race influencing the choice.

Even here, the situation is complicated by possible indirect or institutionalized discrimination. Suppose black people are just as capable of being musicians but have not had access to training. For example, in 1989, the Detroit Symphony Orchestra was threatened with losing a $1.3m subsidy from the state of Michigan unless it hired a second black musician. It side-stepped the blind audition and hired a black man, who noted nonetheless that he would've preferred to be hired normally. This affirmative action hiring was clearly in the narrowest sense discriminatory, yet a chain of events followed leading to the Detroit Symphony African-American Fellowship Program in which young black musicians join the orchestra in rehearsals and performances. They receive coaching and audition preparation tips from orchestra members. Seven Detroit fellows have won seats in major American orchestras.

The key to the paradox is the subjectively interpreted phrase "more favorable treatment". Different people have different ideas about what constitutes "favorable treatment". To a male who does not want to die, favorable treatment means not being forced to go to the frontline. To a female who wants to defend her homeland, favorable treatment means being allowed to defend her homeland.

Different groups of people will have different perceptions of a situation. Four people who witness a car accident will have four different perceptions of what happened and how it happened.

Therefore it is possible to have a situation where two groups of people vehemently oppose each other, both objecting to the same piece of legislation on the grounds that it "gives more favorable treatment" to the other group.