Racism are ideologies and practices that seek to justify, or cause, the unequal treatment of groups that are conceptualized as racially or ethnically different. These can take the form of social actions, practices or beliefs, or political systems (e.g., Apartheid) that consider different races to be ranked as inherently superior or inferior to each other, based on presumed shared inheritable traits, abilities, or qualities. It may also hold that members of different races should be treated differently. Modern variants are often based in social perceptions of biological differences between peoples.