Modern scholarship views racial categories as socially constructed, that is, race is not intrinsic to human beings but rather an identity created, often by socially dominant groups, to establish meaning in a social context. Different cultures define different racial groups, often focused on the largest groups of social relevance, and these definitions can change over time.
- In South Africa, the Population Registration Act, 1950 recognized only White, Black, and Coloured.
- The government of Myanmar recognizes eight "major national ethnic races".
- The Brazilian census classifies people into brancos (whites), pardos (multiracial), pretos (blacks), caboclos, amarelos (Asians), and indigenous (see Race and ethnicity in Brazil), though many people use different terms to identify themselves.
- The United States Census Bureau proposed but then withdrew plans to add a new category to classify Middle Eastern and North African peoples in the U.S. Census 2020, over a dispute over whether this classification should be considered a white ethnicity or a separate race.
- Legal definitions of whiteness in the United States used before the civil rights movement were often challenged for specific groups.
- Historical race concepts have included a wide variety of schemes to divide local or worldwide populations into races and sub-races.
The establishment of racial boundaries often involves the subjugation of groups defined as racially inferior, as in the one-drop rule used in the 19th-century United States to exclude those with any amount of African ancestry from the dominant racial grouping, defined as "white". Such racial identities reflect the cultural attitudes of imperial powers dominant during the age of European colonial expansion. This view rejects the notion that race is biologically defined.
According to geneticist David Reich, "while race may be a social construct, differences in genetic ancestry that happen to correlate to many of today’s racial constructs are real." These biological differences in geographic ancestral populations are not consistent with zoological definitions of race, and there are no "sharp, categorical distinctions".
Although commonalities in physical traits such as facial features, skin color, and hair texture comprise part of the race concept, this linkage is a social distinction rather than an inherently biological one. Other dimensions of racial groupings include shared history, traditions and language. For instance, African-American English is a language spoken by many African Americans, especially in areas of the United States where racial segregation exists. Furthermore, people often self-identify as members of a race for political reasons.
When people define and talk about a particular conception of race, they create a social reality through which social categorization is achieved. In this sense, races are said to be social constructs. These constructs develop within various legal, economic, and sociopolitical contexts, and may be the effect, rather than the cause, of major social situations. While race is understood to be a social construct by many, most scholars agree that race has real material effects in the lives of people through institutionalized practices of preference and discrimination.
Socioeconomic factors, in combination with early but enduring views of race, have led to considerable suffering within disadvantaged racial groups. Racial discrimination often coincides with racist mindsets, whereby the individuals and ideologies of one group come to perceive the members of an outgroup as both racially defined and morally inferior. As a result, racial groups possessing relatively little power often find themselves excluded or oppressed, while hegemonic individuals and institutions are charged with holding racist attitudes. Racism has led to many instances of tragedy, including slavery and genocide.
In some countries, law enforcement uses race to profile suspects. This use of racial categories is frequently criticized for perpetuating an outmoded understanding of human biological variation, and promoting stereotypes. Because in some societies racial groupings correspond closely with patterns of social stratification, for social scientists studying social inequality, race can be a significant variable. As sociological factors, racial categories may in part reflect subjective attributions, self-identities, and social institutions.
Scholars continue to debate the degrees to which racial categories are biologically warranted and socially constructed. For example, in 2008, John Hartigan, Jr. argued for a view of race that focused primarily on culture, but which does not ignore the potential relevance of biology or genetics. Accordingly, the racial paradigms employed in different disciplines vary in their emphasis on biological reduction as contrasted with societal construction.
In the social sciences, theoretical frameworks such as racial formation theory and critical race theory investigate implications of race as social construction by exploring how the images, ideas and assumptions of race are expressed in everyday life. A large body of scholarship has traced the relationships between the historical, social production of race in legal and criminal language, and their effects on the policing and disproportionate incarceration of certain groups.