American speech, government, and multicultural studies typically use the term “minority” loosely to describe virtually any ethnic or gender group that is either non-white or, in gender, non-male or non-heterosexual. In the USA, "minority" is rarely used to describe lower socio-economic classes.
This instructor's multicultural courses define minority as the result of two different attributes—one historical, the other physical or cosmetic:
particular ethnic groups' historical experience of involuntary contact, exploitation, and deprivation instead of opportunity and freedom (as with the immigrant narrative).
distinctive physical markers including the color code.
Majority or mainstream culture is defined by immigration: most Americans or their ancestors voluntarily chose to come to America for rights and opportunity.
Minority cultures, especially African America and Native America, are not immigrants in any standard sense:
African Americans were brought to America involuntarily. Instead of finding opportunity, they found slavery and, later, segregation and continuing discrimination.
Native Americans were already here for thousands of years before modern immigration, which led to catastrophic losses of population, land, and economic infrastructure. Instead of living the American Dream, American Indians suffer the American Nightmare.
New-World Immigrants (Latin Americans and Afro-Caribbeans) may combine immigrant & minority backgrounds and narratives. Especially Mexican-Americans in the Mexican-American War suffered involuntary contact and loss of land comparable to American Indians .
In contrast to immigrant cultures, minority cultures may not assimilate but instead live separately in a distinct community and culture, e. g. black ghettoes, Indian reservations, all-black suburbs. Intermarriage may be limited socially or legally by either side. (This resistance to assimilation may be felt from both sides: the minority group may not want to assimilate to a culture that exploited them; the dominant culture may set laws or barriers to inter-racial marriage, citizenship, voting, participation in other public activities of facilities.)
Distinctive physical markers including the color code.
Through assimilation (especially intermarriage), immigrant cultures become "unmarked": ethnic markers (distinct language, clothes, hair, makeup, perfumes, even physical differences) diminish or disappear.
Minority cultures, esp. with lower rates of intermarriage, may remain "marked" by physical differences (skin color code, body styles, facial features) and cultural styles (e.g. unique names, fashions, speech styles)
Maintenance of such differences reinforces separateness or difference instead of similarity or assimilation.
The minority narrative (African Americans, Native Americans) is not an immigrant story of voluntary participation and assimilation but of involuntary contact and exploitation, resisting assimilation, and creating an identity more or less separate or variant from the dominant culture that exploited them.
The color code or other physical differences are wild-card factors that may enable exploitation and reinforce separateness.
Behavioral or social "symptoms" of minority status. (These behaviors can easily be reassigned to "class status," but in American culture race and class have strong historical and associational bearings on each other.)
mistrust, resistance, or cynicism toward dominant-culture authority figures, especially law-enforcement > lack of faith or participation in system (low voting turnout, school dropouts, indifference to public support groups like PTA, social services, etc.)
deviation from classic "nuclear family" model of two biological parents and directly-related siblings > improvised, extended families; unstable parental bonds
promotion of traditional gender roles, esp. male privilege and womanly submission
family instability (high rates of divorce, lower rates of marriage, single motherhood)
early child-bearing, age at first birth (limited sex education or contraception, intended to inhibit adolescent sexual activity) > limited social and geographic mobility, end of education, cycle of poverty
(class marker for upper class is extended childhood, delayed marriage and child-bearing > family stability, parents established financially)
escapist behaviors like drugs, alcohol, gambling
absence of successful legal models in business, education, etc.
Other ethnic groups that may trend to minority status (sometimes called "downward assimilation," in which people gravitate to the most dangerous aspects of American culture like cynicism, despair, escapism, get-rich-quick schemes, crime, and other "symptoms" listed above.)
Scotch-Irish or White heartland Americans
left behind economically by globalization and de-industrialization
aversion to government and public education
disdain for outsiders or other cultures leading to social isolation (including lack of continuing migration)
maintenance of traditional gender roles and extended families despite nuclear-family breakdown through divorce and lower marriage rates, early child-bearing..