The Motion Picture Association of America (MPAA) is a bit like the sun: It's loomed large in our atmosphere for so long, it's easy to forget how harmful it can be—until, of course, it burns you.

For nearly a century, this massive trade association has represented most major film studios, and it's overseen the film ratings board since 1968. However, the way that those ratings are doled out, particularly the NC-17 rating introduced in 1990, amounts to a form of censorship that filmmakers, journalists and academics have protested for decades. It may be a ubiquitous force, but unlike sunlight, the MPAA hinders growth and creation instead of supporting it.

This raises the question: How has our collective consciousness been shaped by what we haven't seen?

Keeping things kid-friendly

By the 1960s, the MPAA had begun to assume its modern form under its president, Jack Valenti, a lobbyist and political advisor who had served in the Johnson White House. Valenti created the ratings system, ranging from the kid-friendly G to the adults-only NC-17, based on an often invoked but never defined "average American parent" and their standard of