I don't think kids need to be taught racism by their parents or society to notice race. Little kids don't notice a lot of things that they come to notice as they mature. In my public elementary school, black and white kids played indiscriminately together in kindergarten. By second and third grade, most kids sought the company of kids of the same race and gender at recess and lunch. No one was taught to do this. In my school, at that age, there wasn't hatred or fighting or conscious racism. Most people just gravitated to those most like themselves.