At its root is fear. And within it an unwillingness to adapt, a seething attempt at self worth, a boiling animalism that cannot be quenched by lynching or dragging a body behind a pick-up truck until the skin is removed leaving only the skeleton.
It isn't merely distinguishing one by the color of their skin; it is religious, economic, national, birth, party affiliation, gender, physical characteristics, tribal, elitist, biblical, nationalistic, jingoistic, and can only be remedied through acceptance. In other words, the individual must not only be taught that everyone is created equal, but the world must show by example that each human born under the sun is no different than the next. That each individual is no more deserving of clean air and water and love than the next.
A tall order maybe, but one that is within reach because every human, when they are very young, is innocent. Innocent until they are exposed to those who have either been (un)lucky enough to have lived, breathed, survived, experienced, or cultivated racism.