### Instruction: How are racial categories used historically?
### Input: Racial categories have historically been used as a way to enable an oppressive figure or group to discriminate against other groups or individuals which were seen as different from that of the oppressor. In nineteenth and early twentieth century Europe, artwork was a common form of racialization which targeted countries in the Middle East and Asia. The artwork, predominantly paintings, were portrayed in order to instill prejudice in the Western populations through sexualizing and manipulating images. One of the most prominent examples of Orientalist work in art is a piece by Eugène Delacroix titled Women of Algiers in their Apartment. Dating back to 1834, it portrays three women resting in a harem in exotic clothing while an African woman is dressed in plain clothing, depicting her role as a servant. Fine textiles, hookahs, and other paraphernalia adorn the room, which represents a European fantasy of an exotic scene. Attempts to portray these cultures as strange, foreign and exotic through Orientalism led to intolerance towards the Arab and Asian communities in Europe and the United States. Others argue that Delacroix, who travelled in North Africa sketching extensively, was depicting a realistic scene of the era based on his first-hand knowledge and experience. In such an interpretation the clothing, for example, is consistent with the times, as Arab North Africans dressed differently from Europeans, and kept black slaves who would not have been treated as equals.
### Response: Historically, oppressive groups use racial categories to discriminate against other groups that are different from them.