Racism, whether it derives from a (pseudo)scientific source, a sociological source, or a general perception of differences between people, is an ideal that is internally inconsistent, and demonstrates how human perception is flawed.
The belief that there are “groups of people” that can be defined by phenotypical and or genetic “relations” is generally based on the fact that humans are a group oriented animal, and the need for ingroup/outgroup preferences is key for the funtion of human social dynamics. Over the centuries, this behavior has evolved into an idea that there are distinct groupings of human beings that can be determined by examining physical traits (phenotype), genetic traits, behavioral traits, and a combination of those descriptors. The most common racial way of determining “race” is to look at someone’s skin color, and have a fairly rough estimate at what part of the world their family likely came from. Some race realists use genetic studies to link individuals together by defining certain “common genes” that are found within a “certain group of individuals who whole a relation to each other”. Finally, some sociologists and anthropologists believe that race is also a function of behavioral characteristics, much to how certain dog breeds have certain tendencies. All of these descriptors of race are broadly unscientific, and in general are an interpretation of how biology functions, rather than an objective observation, especially with the latter examples of sociology and anthropology.
To give a quick rundown of the philosophy of science, science is meant to function as a falsifiable study of how things function. It requires repeatable experiments with a control group in order to mitigate data noise that naturally occurs. The key word here is falsifiable, which just about every interpretation of race fails to live up to.
To begin with, what even is a race? How does a race “start”? What happens when two people of “different races” have children? Are their offspring “hybrids”? Are they a “new, distinct race”? To create an internally consistent system of measuring what a race is, that is falsifiable, and somehow answers these questions is likely impossible. The beginnings of what a race even is, has no clarity. Biologists today even have difficult differentiating when speciation occurs, that is to say when a new species becomes distinct from a larger group of a certain animal. A classic case occurs with dog breeds. What makes dog breeds distinct? While overall most dog breeds may appear highly distinct, the reality is that all dog breeds are the same, and they have a few characteristics that were specifically bred in order to accentuate those traits. The breeding process usually involves taking dogs that are distantly, or more commonly, closely related, and breeding them together. For this reason, genetic inbreeding is growing ever more common with some breeds, and the majority of non “mutt” breeds overall. With this interpretation of race, race is likely a function of extended population, with some amount of inbreeding over time.
The genetics approach also fails to solve any issues, and runs into many of the same problems that the phenotypical approach has. For example, many racial geneticists will select a certain grouping of genes to test within a population, in order to determine the “racial makeup” of the population. The question of course is, what genes are being selected, and why are those genes in particular a better selection than a certain grouping of other genes? Statistical analysis is generally used as an answer, as statistical models can be accurate at forecasting predicted outcomes. However, this is not scientific because, again, it is unfalsifiable. As with phenotypical examination, simply selecting one group of traits over another only demonstrates that a certain statistical outcome will occur, not that some racial hypothesis exists.
Race is a poor measure of human social groups anyhow. Not only are there a lot of variations within “certain racial groups”, but “racial groups” are constantly intermingling, and as far as recorded human history is concerned, there are very few groups of human beings anywhere on the planet that have lived in contact isolation log enough for serious differences to occur. And even with those few outliers, they are still genetically compatible with the greater human population, and can bear offspring with virtually anyone else on Earth. Even if racial differences do exist, they are such a small piece of the greater human biology that they have virtually no impact on how humans function. People should be treated with a certain baseline level of respect not only because it is the right thing to do, but because treating someone for their “racial characteristics” is silly when considering how small overall “race” actually exists.
Racism is unironically only for small minded people who cannot think that people are more complex than their perceived physical characteristics.