The concept of race signifies the grouping of individual humans by some set of perceived physical characteristics, often called “phenotypes,” which are thought to be inherited through some blood-borne factor. Which specific set of perceived, shared physical characteristics constitute a race varies historically, geographically, socially, and politically. Indeed, there is no biological or genetic foundation for the grouping of individual humans into a racial group. Instead, humans themselves choose (consciously or unconsciously) which physical characteristics constitute a racial group. Consequently, racial groups are presently thought to be social constructions, or a category created not by biological nature but by human invention. However, from its origins in the early modern era until the twentieth century, race was not considered a social construction but a real, biological distinction transmitted from one generation to the next. Thus, racial identity was thought to be something fixed and imposed genetically. . . .
The ambiguities and confusion associated with determining the boundaries of discrete racial categories has over time provoked a widespread scholarly consensus that that race is socially constructed, while advances in the understanding of human genetics has undermined scholarly belief in the biological foundations of discrete races. However, significant scholarly debate persists regarding the relationship between racial groupings and social or political processes. For instance, some scholars suggest that race is inconceivable without racialized social hierarchies, such that racial identities are always organized so that some races are portrayed as superior while others are inferior. In addition, scholars dispute whether racial categories are defined only by members of superior racialized groups or whether subordinate groups themselves contribute to and maintain racial categorization. Finally, there is some controversy as to whether some real genetic differences may validly be used to categorize individual humans into breeding populations, even though these categorizations do not fit the socially constructed racial groups that may be recognized within any given society.