Child development experts say the images that kids see early in life can have a significant long-term effect on their perception of the world. And while a lot of attention is paid to the impact of violent movies and other media, one less-discussed area is on-screen depictions of gender.

Common Sense Media, a nonprofit group that offers recommendations on entertainment content for children, this week expanded its ratings system to indicate how well TV shows and films combat traditional gender stereotypes. It developed the ratings based on scholarly research into gender portrayals in media and a survey of parents.

The group’s research review found that media images have tended to suggest that masculine traits are favored over female ones and that girls should focus on their looks. These images also can lead to tolerance of sexual harassment and reinforce beliefs about what men and women can do. Many parents have concerns about these issues, the survey found, but parents of color were the most worried, citing negative media depictions of children of color.

“We have seen gender roles undergo transformational change over the past half century, but media portrayals have not kept up,”  Olivia Morgan, director of the group’s Gender Equity Is Common Sense initiative, said in a news release. “Most U.S. families depend on a woman’s paycheck, and many men enjoy family responsibilities, yet that is not what’s portrayed on TV and at the movies.”

In comments to The New York Times, Common Sense Media Executive Editor for Ratings and Reviews Betsy Bozdech noted that, while some works clearly bucked gender stereotypes (think A League of Their Own or Billy Elliot), other shows and films that might have looked good on the surface didn’t hit the mark.

Bozdech cited the movie Bridesmaids. “Women can be funny on their own, they can do raunchy comedy, they don’t need guys,” she said. “But there wasn’t necessarily an intent to push against gender stereotypes.”

The new ratings could have wide influence on the media world—the organization’s website gets about 5 million unique visitors a month, and Common Sense Media has standing relationships with major companies. Some advertisers even base their ad buys on the group’s findings, according to the Times.

Common Sense Media says “Bones” is an example of a TV show that includes positive portrayals of gender. (21st Century Fox)