Racism is taught behaviour, as is religious belief, and the two go hand in hand quite often. Nobody is born Racist.
We are born not conscious of race or colour as being anything remarkable
^^^ This is debatable. If racism is taught behaviour, who taught the world's first racist?
Behaviour is a phenotype, coded for by our genes. Although behaviour has a great amount of plasticity and can be taught (some people do learn racism from their parents), behaviour also has an innate aspect - originating from the genes in people's DNA.
Humans have been 'othering' other groups of humans throughout human history. I would suggest that this behaviour is innate.