Present almost at the creation of television broadcasting in the late 1940s, reality TV has developed along with the medium and has changed as the nation changed. From the surprised Americans caught in their most embarrassing moments by Allen Funt's Candid Camera in 1948, to the downto- earth Loud family of An American Family in 1973, to the rat-eating competitors of Survivor in 2002, reality, or unscripted, TV has amused, surprised, and mortified millions of viewers through the years. The changes in program content reflect the changing times: What viewers want to know about the participants as well as what participants allow to be known about them has increased over the years.

For example, post-World War II Americans—new to the nightly entertainment that network television could provide—found the vulnerability of Candid Camera participants caught in just a few minutes of embarrassing film to be sufficiently amusing. Different...