People Just Naturally Like Those who are Similar

You don't have to "like" anyone. But there is a world of difference between forming an opinion and expressing that opinion publically with exhortations to commit violence and discriminatory acts against groups of people based on a broadly defined characteristic. Or to exploit your membership of a majority group in society to disadvantage those deemed not to be part of that group.

I think it's the concept of "the outsider". That starts with the nuclear family. Everyone outside that family is an outsider, with the possible exception of distant family, who may or may not be outsiders.

If the family in question is isolated, or insular, then a degree of culture shock ensues with the introduction of "an outsider". Isolated, or insular, or even ignorant families gradually learn about the huge numbers of "outsiders", and categorize these outsiders by the very few things they might know about those groups.

Categorization normally occurs by nation, then by known cultural differences, and then by possible physical appearances.

Naturally, the more different in culture and appearance the "outsider" might be, the more ALIEN the outsider appears to this insular family.

I believe racism began when insular groups began to categorize other groups as "unacceptable" based on physical appearance or culture.

ever seen a blue bird hanging with a eagle?

they both birds...

Maybe that is why we are here on Similar Worlds to find people having some sort of similarity with us.

What you say is true to an extent... Where the problem lies is this... Do you dislike just because of racial features?

The problem is in what people deem as racism now. The lines are getting blurred and now it’s racism to dislike someone or their way of life.