Humor has historically been tied to the mores of the day. The Yellow Kid was predicated on what people thought was funny about the immigrant Irish. When you're different in a society, you're funny.

In this quote, Will Eisner explores the idea that humor is deeply influenced by the mores (or social customs) of the time. He points out that humor is often shaped by what is considered acceptable or amusing in a given society, and can reflect the societal views and stereotypes of the day. Eisner uses the example of The Yellow Kid, one of the earliest comic strips, which was based on the humor surrounding immigrant Irish communities, highlighting how comedy can be tied to cultural perceptions and prejudices.

Eisner suggests that humor often comes from a place of otherness—when someone is perceived as different in society, whether due to race, ethnicity, or background, they can become the target of humor. He implies that those who stand out or don’t fit into the mainstream are often the subjects of jokes or caricatures. This reflects how humor can sometimes reinforce social divisions and how being "different" can be framed as something amusing or absurd in the eyes of the majority.

The origin of this quote likely stems from Eisner’s deep understanding of comics and graphic novels, where humor and satire have been used as tools to reflect social issues and critique cultural norms. As a pioneer of the comic book industry, Eisner saw firsthand how humor in his work often mirrored the changing attitudes and values of society. He recognized that humor is a tool for both entertainment and social commentary, capable of addressing complex issues while engaging audiences.

Ultimately, Eisner’s quote sheds light on the role of humor in shaping and reflecting society's values. It suggests that comedy is not just for entertainment, but also serves as a means to comment on the cultural dynamics of a time, especially when it comes to issues of identity, otherness, and societal norms. Humor, in this sense, is a reflection of how society views and reacts to difference.