"Racism consists of both prejudice and discrimination based in social perceptions of biological differences between peoples".1 The refraining of the foreign and unknown, for example other cultures, is probably as old as humanity itself. Yet, that is not the same thing as racism. The explanation for the modern racism we do not find in human nature, but later in 1600, 1700 and 1800-century European colonialism and imperialism. Colonialism was greatest during discovery trips time (1400s), because Europeans traveled around the world to take control of areas, and sometimes there were people even in those places. Then they became colonies and had no power to resist the richer countries' power and weapons, the only way was to obey. The first colonial power in India was Portugal, but Britain was the greatest. Imperialism/Colonialism is just another word for racism.
In order to legitimize racism, it has been made "scientific" research that "proves"; the white race according to the laws of nature must reign and other breeds submit. Biological superiority would once and for all justify the slave trade, colonialism and imperialism. In the 1800s there was a whole industry of scientists and politicians who delivered the same message: the White Europeans are the master race and the other has the history doomed to annihilation. For instance, American and physician Samuel Morton (1799-1851) had the largest collection of skulls in his possession. Through measurements he claimed to have proved that white people's skulls were greatest. This in turn would prove the Whites intelligence and superiority. Control statements after Morton's death, however, show a number of mathematical errors and methodological errors. In particular, Morton did not take into account that the size of the head is generally in proportion to body size.2 Sure, you can show some understanding of science at that time was not so developed.