Race is the taxonomic principle of grouping living things based on common heredity, physical attributes, and behavior, and where all members belong to the same species yet appear to warrant further classification. The terms race and subspecies are equivalent: see subspecies for a definition of race in its biological sense, and species for a broader discusion.
Many people believe that physical characteristics of various Homo sapiens (and, according to some, other characteristics such as culture, geography, religion, language and nationality) justify the classification of humanity into various races. This belief emerged during the European Enlightenment and was at that time generally accepted by both the scientific and lay communities.
In the early-to-mid 20th century, however, many biological and social scientists began questioning the relationship between biological and cultural attributes, and some began questioning the taxonomic validity of race. In the decades immediately after the Second World War (in which racial theories were used as justification for enormous crimes), and gaining special momentum in the 1960s (in the context of the U.S. civil-rights struggle and global anti-colonial struggle), many came to reject the concept of race as a biological fact altogether, at least as it applies to humans.
The belief that human subscpecies (races) exist is unquestionably real and, like any belief held by a large number of people, is significant in itself, and significant regardless of its scientific accuracy. The primary impact of race on societies is through the effect the belief in it has on social behaviour (see communal reinforcement for further analysis of this social phenomenon). Nevertheless, it is useful to review the scientific meaning of race as used by biologists in the study of other large organisms, such as mammals, birds, and trees. In biology, a race (or subspecies—the terms are exact equivalents) is a type of recognisable group forming part of a species.
A monotypic species has no races. This can occur in several ways.
A polytypic species has two or more races. These are separate groups that are clearly distinct from one another and do not generally interbreed (although there may be a relatively narrow hybridisation zone), but which would interbreed freely if given the chance to do so. Note that groups which would not interbreed freely, even if brought together such that they had the opportunity to do so, are not races: they are separate species.
Humans clearly vary considerably. By far the greater part of human genetic variation, however, occurs within "racial" groups and the variation between racial groups accounts for less than 10% of the total. Nevertheless, although the difference between "races" is less than 10% of the difference within any particular "race", this does not in itself invalidate the suggestion that there might be different races of Homo sapiens. The rules of biological classification do not set any 'smallest allowable difference' between taxa: any distinct difference is sufficient.
However, a distinct difference is only one of the two conditions that must be satisfied before a different form can be classified as a race or species. The other is lack of significant gene flow between the populations. In the case of human "races", interbreeding is not just possible but widespread: thus they cannot be considered separate species. Given the way that different human "races" fade gradually from one to another in many parts of the world, the overwhelming majority of biologists draw the conclusion that human "racial" variation is in fact clinal, and that the human species is monotypic.
Thus, biologically speaking, Homo sapiens has no races.
Historians, anthropologists and social scientists today are apt to describe the notion of race as a "social construct", using instead the concept of "population" to refer to communities distinguished by characteristic distributions of specified gene variants. The concept of biological race, however, has proved resilient even among those who claim not to harbor unthinking hostility toward historically targeted groups.
This may be a matter of semantics, in that such scientists and laypeople use the word "race" to mean "population," or it may be an effect of the underlying cultural power of the concept of "race" in racist societies. Whether it be "race", "population" or some other appellation, a working concept of sub-specific clustering is crucial because a number of group differences, such as gene mutation profiles strongly linked to certain human subgroups (see Lactose intolerance, Tay-Sachs Disease and Sickle cell anemia), are difficult to address without resort to a category higher than "individual" and lower than "species".
The historical definition of race, before the development of evolutionary biology, was that of common lineage, a vague concept interchangeable with species, breed[?], cultural origin, or national character ("The whole race of mankind." --Shakespeare; "Whence the long race of Alban fathers come" --Dryden[?]).
The 19th-century concept of race was based primarily on morphological and cosmetic characteristics such as skin color, facial type, cranial profile and amount, texture and color of hair. Though such characteristics have since been declared by many experts to have a minimal relationship with any other heritable characteristics, they retain some persuasive force because it is easy to immediately distinguish people based on physical appearance.
Because people of different races can interbreed, this method of classification is weak (compare with species). In other words, racial purity does not have a clear biological meaning. On the other hand, it is clear that for an extended period of time after Homo sapiens' first migrations from Africa (probably around 80,000 BC) and before the rise of wheeled and seagoing transportation (around 3000 BC), geographically isolated groups of people underwent some degree of divergent evolution. Whether that degree was high enough to merit a formal taxon beneath the species level is a complicated issue loaded with semantic and emotional pitfalls for scientists in the field and for those whose work is often based on scientific findings, such as educators, physicians and political officeholders.
Among the 19th-century naturalists who defined the field were Georges Cuvier, James Cowles Pritchard, Louis Agassiz, Charles Pickering[?] (Races of Man and Their Geographical Distribution, 1848), and Johann Friedrich Blumenbach[?]. Cuvier enumerated three races, Pritchard seven, Agassiz eight, and Pickering eleven. Blumenbach's classification was widely adopted:
Writers in the decades following Blumenbach classified the Malay and American races as branches of the Mongolian, leaving only the Caucasian, Mongolian, and Ethiopian races. Further explication in the early and mid twentieth century, notably by American anthropologist Carleton S. Coon, arrived at three primary races (Negroid, Caucasoid, Sinoid) with a small number of less widespread races (especially "Australoid").
The concept of race was applied at the time of Blumenbach by political theorists such as Johann Gottfried von Herder to nationalist theory to develop a militant ethnic nationalism. They posited the historical existence of "races" such as the German and French race, branching from basal races supposed to have existed for millennia, such as the "Aryan" race, and believed political boundaries should mirror these racial boundaries. Later, one of Hitler's favorite sayings was "Politics is applied biology". Hitler's pseudoscientific ideas of racial purity led to atrocities on an unprecedented scale, and "racial cleansing" or "ethnic cleansing" as a sociopolitical motivation or justification has reared its head several times since Hitler (particularly in Cambodia, the Balkans and East Africa). In one sense, such "cleansing" is merely another name for the tribal warfare and mass murder that has afflicted human society from time out of mind. But these crimes seem to gain an extra intensity and thoroughness when the perpetrators believe their acts are sanctioned on scientific grounds.
Racial inequality has been a concern of United States politicians and legislators since the country's founding. In the 19th century most "white" Americans (including abolitionists) explained racial inequality as an inevitable consequence of biological differences. In the second half of the 20th century, political and civic leaders as well as scientists debated whether racial inequality is biological or cultural in origin. On one end of the political spectrum, some argued that current inequalities between blacks and whites are primarily cultural and historical, the result of such historical wrongs as slavery and segregation, and could be redressed through such programs as "affirmative action" and "Head Start." On the other end of the spectrum, a movement to redirect tax money away from remedial programs for minority phenotypes was based on interpretations of aptitude test data which, according to advocates, showed that race-linked differences in basic ability are biological in origin and cannot be leveled even by intensive educational efforts. In electoral politics, many more members of racial and ethnic minorities have won important offices in western nations compared to earlier times, although the very highest offices tend to remain in the hands of racial/ethnic majorities.
In the 19th century many natural scientists made three claims about race: first, that races are objective, naturally occurring things; second, that there is a strong relationship between biological races and other human phenomena (such as social behavior and culture, and by extension the relative material success of cultures); third, that race is therefore a valid scientific category that can be used to explain and predict individual and group behavior. In the 20th century, mainstream anthropologists and others rejected each of these claims, while continuing to study between-group genotypic and phenotypic variations. By the end of the 20th century, most social and many natural scientists turned to the "population" concept to talk about these variations, arguing that accounts of "race" (within both the popular and scientific literatures) are socially constructed. Some social and natural scientists, however, argue that new studies in molecular genetics support a nomenclature strongly reminiscent of traditional racial and ethnic terminology.
Since human beings are the most complex entities we know of, the empirical study of man is in many ways the most difficult of all, making problems in fields like physics and chemistry look elementary in comparison. It is no surprise that fields like anthropology, human genetics and psychobiology[?] are in flux, and the state of these fields may change radically during this century as advances in the more elementary sciences are synthesized into increasingly objective definitions of "human nature". Recognition of sub-specific group traits may find a place in these definitions, probably without, however, the spurious valuations of overall superiority and inferiority formerly attached to them.
The rejection of 19th century assumptions was most effectively initiated by Franz Boas, the founder of American academic anthropology. In the first decades of the 20th century he studied the relationship between race and height in New York City, discovering that the children of immigrants were taller than their parents. Although height is clearly primarily a biological phenomenon, he concluded that an individual's height was determined not only by inheritance but by environment as well (in this case, better pre- and neo-natal care, especially nutrition). Since height, even after accounting for environmental factors, is still at least 80% determined by parental genetics, and since human subgroup height averages irreducibly differ according to that genetic determinant, many of Boas's students accepted the existence of race as a biological fact. But they concluded that there was no relationship between biological race and other human phenomena (such as social behavior, culture, intelligence and morality).
By the 1950s anthropologists had come to question the very existence of race as a biological phenomenon. This rejection was based on three facts. First, they pointed out that the preponderance of evidence suggests that all human beings are descended from a common ancestor (although this fact alone has little bearing on the subsequent formation or non-formation of new subgroups). Second, they observed that there are many biological differences between people that are not taken into account by race (for example, blood type). Finally, they pointed out that oftentimes the genetic differences between members of the same race are greater than the average genetic difference between races. For example, the variation in blood types within specific groups is 85%, but the total variation between groups is only 15% (see the American Anthropological Association's Statement on Race  (http://new.aaanet.org/stmts/racepp.htm)). Those who continue to believe in the real existence of biological race, or in genetic clusters similar to race, point out that in determining overall relatedness the entire genetic cohorts of groups must be compared. When this is done, a grouping pattern emerges that closely follows traditional race groupings. For example, it is true that the so-called "Negroid" race contains more in-group variation than the other major races. Great differences in height, for instance, can be found within a small geographical area (the "pygmies" are the shortest people in the world on average, while their neighbors, formerly known as "the Watusi", are the tallest). These two "negroid" subgroups vary more from each other in height than either does with the averages for height in the other two major races. However, if total genetic cohorts are used rather than limited sets of traits like height and blood type in an effort to find true overall relatedness, it is seen that any two "negroids" will share a much higher net genetic affinity with one another than either will with any individual of the other two major races. The same is true for any two caucasoids and any two sinoids (see conclusions of the Human Population Genetics Laboratory headed by L. Luca Cavalli-Sforza at  (http://hpgl.stanford.edu/publications/AHG_1996_v60_p401-408.pdf)).
The rejection by mainstream academics of race as a biological phenomenon has important consequences. First, anthropologists (and other biological scientists) developed the notion of "population" to take the place of race. This substitution is not a matter of semantics. It is a statistical phenomenon; as such it does not necessarily (and in fact often does not) have clear boundaries, and it changes over time.
The "populationist" view does not deny that there are physical differences among people; it simply insists that "race" is not useful in analyzing these differences scientifically. Take one of the most obvious physical markers of race, for example – skin color. It is true that the color of people's skin varies. It does not vary according to culture. All people whose ancestors lived in the tropics -- whether in South America, Africa, or Asia, have dark skin. This is because the tropics receive a lot of sunlight, and people with light skin would suffer from excess vitamin D levels; they can sunburn too easily, are more susceptible to disease, and less efficient at sweating. Dark skin is more advantageous. Light skin is found in temperate zones, where it prevented rickets due to inadequate vitamin D. But skin is only one phenotypic trait. Many things play a role in skin color -- exposure to sunlight, ultraviolet radiation, amount of clothing. Many traits are determined by non-genetic factors (as Boas' study of height showed). Moreover, specific traits are not necessarily connected to one another – biological traits such as skin color, hair type, and facial features do not vary together. Finally, the natural distribution of human phenotypes exhibits gradual trends of difference across geographic zones, not the categorical differences of race. Consequently, there are many peoples (like the San of S. W. Africa, or the people of northern India) who have phenotypes that do not neatly fit into the standard race categories. In short, attempts to construct biological racial classifications have been largely overthrown because genetic and phenotypic traits do not vary together over time. Races were often based on a limited number of arbitrarily selected phenotypic traits. Thus, "race" has not explained phenotypic variation between populations. Rather than attempt to classify humans into racial categories, many anthropologists and biologists instead use the notion of population to try to understand why and how biological variation occurs.
Since the 1960s, most anthropologists and teachers of anthropology have re-conceived "race" as a cultural category, in other words, as a particular way some people have of talking about themselves and others. As such it cannot be a useful analytical concept; rather, the use of the term "race" itself must be analyzed. Moreover, biology will not explain why or how people use the idea of race: history and social relationships will. A smaller number of anthropologists and human geneticists argue that race is indeed a valid and valuable concept and that those holding the majority view allow their social consciences (laudable per se) to confuse and delay accurate interpretations and applications of empirical data. They are not convinced by the substitution of the term "population" for the term "race", because it leads to a potentially harmful imprecision in communication (for example, when one could simply say "caucasian" one is instead compelled to say something like "an individual of the western Eurasian population", and when that individual doesn't happen to currently reside in western Eurasia one must say "an individual whose ancestors were of the western Eurasian population"). This position recently received a boost from genetic studies at the molecular level which show characteristic allele signatures for the groups traditionally identified as the three major races, resulting in maps that clearly delineate genetic clines summarized quite well by longstanding racial and ethnic appellations. Precision and commonality in terminological communication is especially important in fields like medical research and diagnosis because a rapidly growing list of genetic disorders and predispositions are strongly linked to race and ethnicity (not to geographical "populations"). If "races" is too freighted a term for these clines then new, convenient, non-academic terminology free of spurious valuations of superiority and inferiority should be developed whether social sensitivities are ruffled or not.
Two examples, one from the United States and one from Brazil, further illustrate the majority view.
In the United States in the 19th century, African-Americans, Native Americans, and European-Americans were each classified as different races. But the criteria for membership in these races were radically different. The government considered anyone with "one drop" of Black blood to be Black. In contrast, Indians were defined by a certain percentage of "Indian blood". And to be White one had to have "pure" White ancestry. These differing criteria for membership in particular races has little to do with biology and much to do with political relations between Blacks and Indians on the one hand, and Whites on the other. By these criteria, it was very easy for a child to be categorized as Black. This likely reflects the requirements of the slave-economy of the U.S. South, for the vast majority of slaves were classified as Black. Even the child of an enslaved African woman and a White master was considered Black, or "of African descent." More importantly, such a child would be a slave. In comparison, it was harder for a child to be classified as Indian. After a few generations of inter-racial marriages, a child might not be considered Indian at all. This likely reflects the requirements of the U.S. economy during the period of westward expansion, although the greater outward similarity of "Whites" and "Indians" surely came into it. Indians had treaty rights to land, but if an individual with one Indian great-grandparent was no longer classified as Indian, they would lose special rights to land. At a time when Whites ruled both Blacks and Indians, it is no coincidence that the hardest race to prove membership in was White.
Compared to 19th century United States, 20th century Brazil was characterized by a relative absence of sharply defined racial groups. This pattern reflects a different history and different social relations. Basically, race in Brazil was biologized, but in a way that recognized the difference between ancestry (which determines genotype) and phenotypic differences. There, racial identity was not governed by a rigid descent rule. A Brazilian child was never automatically identified with the racial type of one or both parents, nor were there only two categories to chose from. Over a dozen racial categories would be recognized in conformity with the combinations of hair color, hair texture, eye color, and skin color. These types grade into each other like the colors of the spectrum and no one category stands significantly isolated from the rest. That is, race referred to appearance, not heredity.
One of the most striking consequences of the Brazilian system of racial identification was that parents and children and even brothers and sisters were frequently accepted as representatives of opposite racial types. In a fishing village in the state of Bahia an investigator showed 100 people pictures of three sisters and were asked to identify the races of each. In only six responses were the sisters identified by the same racial term. Fourteen responses used a different term for each sister. In another experiment nine portraits were shown to a hundred people. Forty different racial types were elicited. It was found, in addition, that a given Brazilian might be called by as many as thirteen different terms by other members of the community. These terms are spread out across practically the entire spectrum of theoretical racial types. A further consequence of the absence of a descent rule was that Brazilians apparently not only disagreed about the racial identity of specific individuals, but they also seemed to be in disagreement about the abstract meaning of the racial terms as defined by words and phrases. For example, 40% of a sample ranked moreno claro as a lighter type than mulato claro, while 60% reversed this order. A further note of confusion is that one person might employ different racial terms for another person over a short time. The use of term varies with the personal relationship and mood. Consequently, people change their racial identity over their lifetimes. This is not the same as "passing" in the USA. It does not require secrecy and the agonizing withdrawal from friends and family that are necessary in this country and among Indians of highland Latin America. In Brazil passing from one race to another occurs with changes in education and economic status. A light skinned person of low status is considered darker than a dark skinned person of high status.
So although the identification of a person by race is far more fluid and flexible in Brazil than in the USA, there are racial stereotypes and prejudices. African features were considered less desirable; Blacks were considered inferior, and Whites are considered superior. These stereotypes are obvious relics of the slave-based plantation system, and say more about history than actual behavior. But the complexity of racial classification in Brazil bears testimony not only to the amount of intermarriage in the post-slavery period, but also to the possibilities of upward mobility. A Brazilian is never merely black or white or some other race; he is rich, well-educated, or poor and uneducated. It makes more sense to say that it is one's class and not one's appearance that determines who will be admitted to hotels, restaurants, and social clubs; who will get preferential treatment in stores, churches, and hotels; and who will have the best chance among a group of marriage suitors – and color is one of the criteria of class identity, but it is not the only one. (This case is taken from Marvin Harris' excellent short study, Pattens of Race in the Americas)
Lately people have tried to associate race and intelligence. This is not new. But most contemporary experts argue that it has always been wrong. It is wrong not because all people are created equal – perhaps we should all have equal rights – but all people are created different, with different abilities and talents. It is wrong because these differences have nothing to do with race (they probably do have something to do with genetics, but the relationship between genotype, phenotype, and environment is too complex to be reduced to the notion of race; see Biology as Ideology by R.C. Lewontin). This is so not only because race is a cultural and not biological category. It is so because intelligence is also a cultural category. See the American Anthropological Association's Statement on Race and Intelligence  (http://new.aaanet.org/stmts/race.htm). The strongest dissent to this opinion can be found in the works of Arthur Jensen, Professor of Educational Psychology at the University of California, Berkeley. Jensen's extensive primary research in the field has, he claims, found a high heritability of "the intelligence factor" with statistically significant genotype-based variation between populations.
In his book The Mismeasure of Man, Stephen Jay Gould, a Harvard paleontologist better known for his popularizing articles in Natural History Magazine (which have been collected in a variety of mass-marketed books) makes three criticisms of Jensen's work. The first criticism is also the criticism most commonly leveled against Jensen by other anthropologists and biologists: that Jensen misunderstands the concept of "heritability." Heritability measures the percentage of variation of a trait due to inheritance, within a population. Jensen, however, has used the concept of heritability to measure differences in inheritance between populations (Gould 1981: 127; 156-156). The second criticism is relatively minor: Gould disagrees with Jensen's support of the attempts of others to calculate the IQ of dead people (such as the famous Polish astronomer and Prussian monetary theorist Copernicus) (1981: 153-154). The third criticism is significant: Gould disagrees with Jensen's belief that IQ tests measure a real variable called g or "general intelligence," which can be measured along a unilinear scale. This is a claim most closely identified with Cyril Burt and Charles Spearman[?]. According to Gould, Jensen misunderstood the research of L. L. Thurstone[?] to ultimately support this claim; Gould however argues that Thurstone's factoral analysis of intelligence revealed g to be an illusion (1981: 159; 13-314). Jensen made a very strong reply to Gould in the summer 1982 issue of Contemporary Education Review (see  (http://www.wcotc.com/euvolution/articles/gould01)).
Recent genetic analyses have enable the concept of race to be represented in somewhat cladistic terms. These studies have indicated that, as already known, Africa was the ancestral source of all people. Australian aborigines were found to be an early out-group that remained isolated. All other groups, including Caucasians, Asians, and Native Americans, were found to be a single related (monophyletic) group resulting from a later out-migration from Africa, which could be reasonably be divided into more or less the equivalents of Caucasian and Sinoid groups, although, of course, recognizing that there are many intermediates. Now, the problem arises of distinguishing black Africans as a racial group; it doesn't work because it is a paraphyletic classification -- that is, to take black Africans as a racial group, the group by definition includes every living person on Earth because everyone is descended from this group. And, of course, it's long been known that groups such as the Khoi-San are as different from other sub-Saharan groups as are Caucasians and Asians.
Because individual geography, culture, religion, political association and, above all, heredity can change, racial purity, the concept that wholly distinct racial groupings exist, has little meaning from the perspective of evolutionary biology.
Ethnicity is the concept of race decoupled from national affiliation. For example, ethnic Germans are people who are not citizens of the nation of Germany but who may be considered racially German.