Comedic foil

A double act, also known as a comedy duo, is a comic pairing in which humor is derived from the uneven relationship between two partners, usually of the same gender, age, ethnic origin and profession but drastically different in terms of personality or behavior. Often one of the members of the duo—the straight man, feed, dead wood, or stooge—is portrayed as reasonable and serious, while the other one—the funny man, banana man or comic—is portrayed as funny, less educated or less intelligent, silly, or unorthodox. If the audience identifies primarily with one character, the other will often be referred to as a comic foil. The term "feed" comes from the way a straight man is wont to set up jokes and "feed" them to his partner.

Despite the names often given to the roles, the "" need not be humorless and it is not always the comic who provides the act's humor. Sometimes it is the straight man who gets the laughs through his or her sarcastic reactions to the comic's antics, as was often the case with Stewart Lee's deadpan, reasoned reactions to Richard Herring's more ridiculous antics in their pairing. Where the "straight man" serves no personal comic purpose but acts as a device to make the "comic" look good, he is known as a "stooge". This is sometimes considered a derogatory term. Most often, however, the humor in a double act comes from the way the two personalities play off each other, rather than from the individuals themselves. In many successful acts the roles are interchangeable.

The template for the modern double act began in the British music halls and the American vaudeville scene of the late nineteenth century. Here, the "straight man" was a necessity, as he would repeat the lines of the "comic". This was done simply because the audience would be noisy, and repeating a joke gave the audience a better chance of hearing it. Soon the dynamic developed so that the "straight man" became a more integral part of the act, setting up jokes to which the comic could then deliver the "punchline." At various stages, acts such as George Burns and Gracie Allen (who, unlike their incarnation on television and in films, operated with Burns as the comic), Abbott and Costello, Flanagan and Allen, Gallagher and Shean, and Smith and Dale were all popular draws. The dynamic continued to develop, with Abbott and Costello using a modern and recognizable formula in routines such as Who's On First? in the 1930s and Flanagan and Allen using "cross talking".

...
Wikipedia