Race realism is the view that biological (genetic) human races exist, in opposition to race denialism, such as considering races arbitrary social constructs. Critics tend to dislike the term race realism and to prefer terms such as racialism, easily confused with racism.
Arguments regarding the existence of races
Jean Philippe Rushton stated in 2002:
Today most scientists and historians engaged in the serious study of race do so from either the race-realist or the hermeneutical perspective. On one side, those I have termed race-realists view race as a natural phenomenon to be observed, studied, and explained. They believe human race is a valid biological concept, similar to sub-species or breeds or strains. On the other side, those I term the hermeneusticists view "race" as an epiphenomenon, (like gender as opposed to "sex") a mere social construction, with political and economic forces as the real causal agents. Rather than actually research race, hermeneuticists research those who study race. Alternative and intermediate positions certainly exist, but the most heated debate currently takes place between advocates of those polar positions.
The race-realist approach is empirical and employs a myriad of scientific methodologies, including surveys, social demography, IQ and personality tests, and behavior genetic analyses (e.g. twin studies). The hermeneutical approach relies on textual, historical, and political analysis. The race-realist viewpoint is descriptive, explanatory, and typically avoids prescribing policy. Because the hermeneutical viewpoint sees inexorable links between theory and practice, its writings are often prescriptive and assume an advocacy position. To their opponents, the race-realist approach comes across as cold, detached, and suspect of hiding a "racist" agenda. Hermeneuticists appear to race-realists as muddled, heated, and ideologically committed to an anti-racist activism.
- Forensic anthropologist George W. Gill, in 2000:
"The idea that race is ‘only skin deep’ is simply not true.” 
- Neil Risch, Professor in Human Genetics and Director of the Center for Human Genetics at the University of California, San Francisco, in 2005:
"if you expect absolute precision in any of these definitions, you can undermine any definitional system. Any category you come up with is going to be imperfect, but that doesn't preclude you from using it or the fact that it has utility. We talk about the prejudicial aspect of this. If you demand that kind of accuracy, then one could make the same arguments about sex and age! You'll like this. In a recent study, when we looked at the correlation between genetic structure [based on microsatellite markers] versus self-description, we found 99.9% concordance between the two. We actually had a higher discordance rate between self-reported sex and markers on the X chromosome! So you could argue that sex is also a problematic category. And there are differences between sex and gender; self-identification may not be correlated with biology perfectly. And there is sexism. And you can talk about age the same way. A person's chronological age does not correspond perfectly with his biological age for a variety of reasons, both inherited and non-inherited. Perhaps just using someone's actual birth year is not a very good way of measuring age. Does that mean we should throw it out? No. Also, there is ageism—prejudice related to age in our society. A lot of these arguments, which have a political or social aspect to them, can be made about all categories, not just the race/ethnicity one."
- Louis Leakey in The Progress And Evolution Of Man In Africa (Oxford University Press, 1961):
"As a social anthropologist, I naturally accept and even stress the fact that there are major differences, both mental and psychological, which separate the different races of mankind. Indeed, I would be inclined to suggest that however great may be the physical differences between such races as the European and the Negro, the mental and psychological differences are greater still."
- Hans Eysenck, Professor of Psychology at London University in 1971:
"All the evidence to date suggests the strong and indeed overwhelming importance of genetic factors in producing the great variety of intellectual differences which we observe in our culture, and much of the differences observed between racial groups."
- Richard Dawkins in The Ancestor's Tale (2004):
"However small the racial partition of the total variation may be, if such racial characteristics as there are highly correlated with other racial characteristics, they are by definition informative, and therefore of taxonomic significance."
"So clearly differentiated are the types of mankind that, were an anthropologist presented with a crowd of men drawn from the Australoid, the Negroid, East Asian or Caucasoid types, he could separate the one human element from the other without hesitation or mistake."
- Rushton, J. P. (2002). The Pioneer Fund and the scientific study of human differences. Albany Law Review, 66, 207-262 http://psychology.uwo.ca/faculty/rushtonpdfs/ALR.pdf
- Gitschier J (2005) The Whole Side of It—An Interview with Neil Risch. PLoS Genet 1(1): e14. http://dx.doi.org/10.1371/journal.pgen.0010014
- Keith, A. (1922). The dawn of national life. In J. A. Hammerton (Ed.). Peoples of All Nations. London: Amalgamated Press. p. xviii.