Answer:
Social beliefs and practices, peer pressure/social pressure, tradition, social media, etc.
Explanation
Social beliefs: Social beliefs are the beliefs by which groups in a community identify themselves. Which leads to peer pressure.
Peer pressure: If an individual is placed into a society where they conform to the physical attributes that are shared with the racist individuals it will be a make or break situation. Peer pressure has been known to be very successful in manipulating humans, from smoking cigarettes because it was cool in the 50's, engaging in risky or illegal behavior because an individual wants to fit in, or even openly showing racism because you will be outlasted or judged because of ones differences in opinion. Judgement clouds reality and creates a disillusionment of what is true which creates habits of closed mindedness or bias.
Tradition: A tradition is defined as the transmission of customs or beliefs from generation to generation, or the fact of being passed on in this way. It starts at home, no child is born racist. Recent brain research indicates that birth to age three are the most important years in a child's development. And along with walking, talking, and all the other norms of infancy, if you teach a child to dislike or see another human beings color as different or ugly from yours then they will have a bias from the start.
Social Media:
Social media played a huge role in the rise of racism, from the depiction of Jim Crow, a clumsy, dimwitted black slave. To the depiction of African American men being violent, uneducated, gang affiliated,individuals. And as Malcolm X once stated, " If you're not careful, the newspapers will have you hating the people who are being oppressed, and loving the people who are doing the oppressing."