The good news is that children who form no racial stereotypes have been found. The bad news is, they have a serious mental deficiency which leads them to be too friendly to strangers. Nature magazine daren't derive the idea that ethnic identity is adaptive.

http://www.nature.com/news/2010/100412/full/news.2010.176.html

"The obvious conclusion, Meyer-Lindenberg says, is that social fear is not required for gender stereotyping, but it is important in forming racial stereotypes". To me, the 'obvious conclusion' is that racial identity is genetically normal. Which does not mean I ADVOCATE racial identity. Heterosexuality is also adaptive, but I don't advocate it, nor believe in discrimination against gays. But neither do I believe in discrimination against straight people. If ethnic identity is adaptive, it should not be discriminated against by calling it 'racism'.