George and Lennie friendship is strong the are the only men on the ranch who are that close, most of the men on the ranch are lonely and they don't have anyone to talk to or rely on.
Loneliness: most of the men on the ranch are lonely and isolated, some of the men go crazy and lose their sense of human because of how lonely the are.
Loneliness plays a big role in the 1930's where people are isolated and are all left alone to find their American dream, some of them succed but most of them fail to accomplish there dreams.