The topic of race in humans is one the most charged issues in history, and racism has led to terrible acts against nations and ethnic groups. Does classification of humans into races even have a scientific basis?

Genetics is a branch of biology that deals with the study of genes, genetic diversity, and heredity. But sometimes geneticists are forced to get involved in sociological subjects, such as the discussion of the term “racial purity.” “Race” is a sociological term, which was applied to classify humanity into groups of shared ethnic origin. The classification is mostly based on external features, but may also be based on other principles, such as geographical region.

Various racial supremacy advocacies and other myths regarding “racial purity,” are all too common around the world. For example, lactose intolerance – the inability to digest the lactose in milk – is more prevalent among certain non-white ethnic groups, giving rise to the false perception that a lactose intolerant person is of mixed descent, insinuating the “suspicion” of not having a “pure” racial ancestry. In this context, it should be noted that lactase, the enzyme responsible for breaking lactose into glucose and galactose, is not exclusive to a specific population group, and around 65% of all humankind suffer lactose intolerance to some degree. Moreover, a study conducted on the subject found that there was no statistically significant connection between ethnicity, age, or gender and lactose intolerance. And yet, this strange myth led to the phenomenon of white supremacists gulping together liters of milk.

Eugenics: genetic improvement of the human race

Eugenics is a biological-sociological philosophy tracing the effects of heredity on human mental and behavioral features, with the aim of discovering and employing ways to improve the human race. This framework of beliefs and practices was especially popular in the United States and in Western Europe at the start of the 20th century, growing in parallel to the development of Mendelian genetics. The eugenic movement was infamous for its attempts to divide society into people with “superior” genes and people with “inferior” genes, and for promoting reproductive programs for people deemed “fit” to reproduce, and sterilization programs meant to inhibit the reproduction of the “flawed” people.

Eugenics had a significant influence on the development of Nazi Germany’s racial ideology. Therefore, the movement’s popularity plummeted after World War II, and its affiliation with the horrors inflicted by the Nazis made it loathsome to the majority of the scientific community. But in the first half of the 20th century, eugenics organizations operated in more than 30 countries, differing from one another in their goals, characteristics, and mode of operation.

During the British mandate in Israel, eugenics was received positively by leading figures in the developing Jewish medical establishment. Dr. Joseph Meir (for whom the Meir hospital is named) was a prominent eugenisict of the time, who endorsed ideas such as castration of mentally ill individuals, encouragement of increased birthrate in “intelligent” families, and placing birthrate restrictions on “poor families of eastern descent.” While these ideas were not implemented in Israel, the medical establishment clearly encouraged them by trying to persuade those involved.

In the last two decades, researchers have begun to question whether World War II had attracted excessive objection to eugenics, and ethical questions which engaged eugenicists from the 20th century have resurfaced. Some view certain decisions enabled by modern medicine – for example, the option of terminating pregnancy of a fetus with disabilities – as a new form of eugenics, which perhaps conforms to values common in the 21st century.

The statistics of racial classification

As the science of genetics advanced over the 20th century last few decades, mostly due to completion of the human genome mapping project, researchers developed new tools to classify humanity into genetically related groups.

While some correlation was found between groupings according to genetic markers and groupings according to traditional racial features (such as skin color), the match is far from perfect. This is because of the overlap among different groups, and the fact that the majority of human traits are continuous and not discrete – for example, it is difficult to determine the precise color shade in which “green” eyes become “blue.” Moreover, the genetic diversity within each group, or race as it is socially perceived, is vast – sometimes greater than the diversity between groups. Therefore, if we were to group the world’s population according to general genetic similarity, as opposed to classification according to genes related to skin color, the result would be different from what we generally perceive as races. This way of classification would necessarily be arbitrary and lack clear boundaries, due to the continuity of human characteristics. For these reasons, there is a general agreement between geneticists that the term “racial purity” and the classification into races in itself is scientifically meaningless. “Pure” races do not, and cannot, exist: Genetic mixing between populations, stemming from population migrations, has been around from the dawn of humanity.

The American Society of Human Genetics (ASHG) responded to the resurgence of racist groups that object to the existence of genetic diversity in what is termed a “pure race,” and who use contorted genetic terminology to support false claims of white supremacy. The ASHG condemned the misuse of the science of genetics to support racist ideologies, and encourages its members to be more politically and socially active. ASHG members published a statement on the matter, explaining that the genetic diversity in the human genome is continuous, so that it is impossible to set clear boundaries between groups in a population. For example, from “black” to “white” there is a continuous range of skin colors. Despite the fact that genes affect human traits, and being born into a racial group could be related to physical appearance, race in itself, as it pertains to humans, is a social construct and not a scientific one. Therefore, any claims of comparative racial superiority or inferiority are not scientific, but rather, stem from a distortion of science.