(AgapePress) - "Oh, come on, Mom! Why can't I go? My friends are going. And it's only rated PG-13!"

How many parents have had arguments with their children about the appropriateness of a film, only to hear the child defend the movie because of its rating?

The truth of the matter is that movie ratings may not be very effective as a guide for careful parents, who are trying to shield their kids from objectionable material.

MPAA Rating System
The movie rating system has been in existence for almost 40 years. It was created as a voluntary system in 1968 by the Motion Picture Association of America (MPAA), with the expressed purpose of helping parents determine what films are appropriate for their children.

The MPAA rates hundreds of movies every year. According to a recently released study from the Kids Risk Project at the Harvard School of Public Health (HSPH), between July 1, 1996 and December 31, 2003, the MPAA rated over 5,600 films released during that period.

The MPAA employs a panel of adults -- who are anonymous to the public and to movie studios -- which issues the familiar G, PG, PG-13 and R ratings based on a film's age-appropriateness. (The NC-17 rating, which replaced the older "X" rating and restricts a movie to an adult audience, is rarely issued by the MPAA.)

The MPAA also makes available limited explanations to provide reasons for a particular rating. For example, the MPAA said the recently released sci-fi movie, Alien vs. Predator, was rated PG-13 for "violence, language, horror images, slime and gore."

Ratings Creep
Most parents have given the rating system high marks as a useful tool in helping them discern whether a particular movie is appropriate for their children. According to the MPAA website, a recent survey by an independent polling firm noted that 76 percent of parents with kids under age 13 found the movie ratings either "very useful" or "fairly useful" in making such decisions.

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However, parents may be unaware that there are subtle shifts occurring with the ratings. According to the HSPH study, there appears to have been an increase in the amount of objectionable content allowed in the ratings categories, a tendency called "ratings creep."

The HSPH study examined movies and their ratings between 1992 and 2003, obtained from the MPAA and two independent movie review sources, Kids-in-Mind and Screen It!. (See box at left.)

"The findings demonstrate that ratings creep has occurred over the last decade and that today's movies contain significantly more violence, sex, and profanity on average than movies of the same rating a decade ago," said Kimberly Thompson, the study's co-researcher and director of the Kids Risk Project.

An article in USA Today highlighted the HSPH study, and noted the practical effect of "ratings creep." For example, the PG-13 film Forrest Gump, released in 1994, had less sex and violence than 2002's PG-13 Minority Report.

Thompson told USA Today, "This raises the question of 'What does PG really mean?' If parents are basing their experience on [movies] a long time ago, maybe they need to get recalibrated. The reality is, the ratings don't mean what they did 10 years ago."

This is not a mere coincidence, according to the HSPH report, but seems to be the product of an actual shift in how the MPAA perceives content. Thompson and study co-author Fumie Yokota, a former HSPH researcher, found "a significant increase of violence, sex and profanity in films over the 11-year period, suggesting that the MPAA became increasingly more lenient in assigning its age-based movie ratings."

A 'Trojan Horse'?
The phenomenon of ratings creep has come at the same time that economic pressure has grown on filmmakers, something that appears quite suspicious to World magazine culture critic Gene Edward Veith.

"The fact is, economic pressure is forcing Hollywood to make fewer R-rated movies and more fare that can draw in audiences of all ages," said Veith. "And yet, filmmakers are manipulating the rating system to keep the raunch factor high."

Veith believes it is not a coincidence. "It's a clear case of collusion," he insisted. "The ratings board is clearly under the control of the studios it is supposed to regulate. The board is changing its standards to maximize the studios' profits."

Nell Minow, author of The Movie Mom's Guide to Family Movies, agrees, and contends that this makes the MPAA rating system virtually meaningless as a parental tool. "It was intended to give parents the information they need to decide what is appropriate for their children, based on their values," she said. "Instead it is cynically manipulated and ultimately deceptive."

In a USA Today op-ed piece, film critic Michael Medved accused the big film studios of the "flagrant abuse of their own rating system." He said, "The PG-13 category has become, alas, the Trojan horse in the movie-rating system -- allowing wildly unsuitable material to smuggle its way past walls erected by even the most protective parents."

Even filmmakers sometimes get confused about what a particular rating means. "It used to be you could use the 'f-word' once and still get a PG-13," said Fox film executive Tom Sherak. "Then it was twice. Now it can be three times, as long as the usage is not sexual. Frontal nudity used to be an X or an NC-17. Now it can be an R. It's always changing. And it depends on the film."

Study Suggestions
The HSPH study recommended that the MPAA follow the approach taken by organizations like Kids-in-Mind and Screen It!, by using clearer criteria in its ratings categories and including more descriptive information about a movie's content.

It also suggested the development and creation of a "universal media rating system," which would use the same types of ratings and symbols across the media spectrum: movies, television, videos, DVDs, and video games.

"A single system would provide the simplest tool for parents, if one can be designed and effectively implemented, and it promises greater clarity and transparency in media rating information," Thompson said.

In the end, however, since information outlets like Kids-In-Mind and Screen It! do exist, the HSPH report considered parents the most effective guardian for children, a conclusion shared by Steven Greydanus of Decent Films, a Christian movie review website. After cautioning readers that the Harvard study is limited only to data from the last decade, Greydanus advises: "Parents shouldn't count on the MPAA system to do their job for them. No matter what the rating is, parental guidance is always required."