"It is important to recognize that humor is fundamentally a social phenomenon; other people provide the context in which we experience humor...humor occurs in nearly every type of interpersonal relationship. We laugh and joke much more frequently when we are with other people than when we are by ourselves (R. A. Martin & Kuiper, 1999); Provine & Fischer, 1989). People do occassionally laugh when they are alone, such as while watching a comedy show on televion, reading a humorous book, or remembering a funny personal experience. However, these instances of laughter are still "social" in that they involve the imagined or implied presence of other people (Allport, 1954). One is still responding to people as characters in the television program or the book, or reliving in memory an event that involved other people. Humor essentially is a way for people to interact in a playful manner."
pg.2