peanut gallery

Etymology:

• The phrase comes from nineteenth-century vaudeville theatres and refers to the cheap seats at the back of the theatre or in the upper balcony. It came to be applied to other venues as well, referring to the section where less-educated or less-seriously-interested patrons sat. The "peanut" comes from the popularity of that cheap snack in those sections, and the possibility that patrons might throw peanuts at the stage if displeased.
• In the mid-twentieth century, the "Howdy Doody Show" associated "peanut gallery" specifically with children.