Racism is the lowest, most crudely primitive form of collectivism. It is the notion of ascribing moral, social or political significance to a man’s genetic lineage—the notion that a man's intellectual and characterological traits are produced and transmitted by his internal body chemistry. Which means, in practice, that a man is to be judged, not by his own character and actions, but by the characters and actions of a collective of ancestors.
Racism claims that the content of a man’s mind (not his cognitive apparatus, but its content) is inherited; that a man’s convictions, values and character are determined before he is born, by physical factors beyond his control. This is the caveman’s version of the doctrine of innate ideas—or of inherited knowledge—which has been thoroughly refuted by philosophy and science. Racism is a doctrine of, by and for brutes. It is a barnyard or stock-farm version of collectivism, appropriate to a mentality that differentiates between various breeds of animals, but not between animals and men.
Like every form of determinism, racism invalidates the specific attribute which distinguishes man from all other living species: his rational faculty. Racism negates two aspects of man’s life: reason and choice, or mind and morality, replacing them with chemical predestination.
--- from The Virtue of Selfishness by Ayn Rand.