In this book Steinbeck explored discrimination of women, black people, and mentally retarded people, as well as the attitudes toward minority groups that existed in the late twenties and early thirties. The minority group focused upon in the book is that of mentally retarded people, personified by Lennie. A second focus of discrimination in the book is black people, represented by Crooks. The last but not least discriminated against group is women such as Curley's wife.

Lennie, a mentally retarded adult, is the main character in the book. He doesn't get as much respect as most of the other characters. "That was a lie, if I were a relative of yours I'd shoot myself." Steinbeck 24. Lennie, as most other mentally retarded people, is not treated civilly by anyone he encounters in the story. An example of the lack of respect shown Lennie. George says, "Well, he seen this...