That's because one of its directors, Jennifer Lee, is female, and so are its lead characters.
Just 1.9% of the directors of 2013's top-grossing films were women — a six-year low — and just a quarter of all the speaking roles in animated films belonged to girls or women, researchers found.
The study by USC's Media, Diversity, & Social Change Initiative, which evaluated more than 25,000 speaking characters in 600 top-grossing films between 2007 and 2013, found that women continue to be underrepresented both behind and in front of the camera, especially in the genres of animation and action-adventure.
"As Hollywood moves to more serialized content, comic books, tent-poles, this is where we see a big problem," said USC Annenberg associate professor Stacy L. Smith. "Action-adventure and animation are pulling very heavily male."
On screen, women were most represented in comedies, with films such as "The Heat,"
Women were least represented in action-adventure films. Marvel movies such as "The Avengers" and fantasy and science fiction franchises like
Women behind the camera, meanwhile, are scarcer than ever, according to the study. In addition to the low percentage of directors, just 7.4% of writers of the top-grossing movies were women, also the lowest percentage in six years.
"Women just aren't moving into the higher-budgeted, top-grossing fare," Smith said, contrasting the numbers to research USC has conducted into independent film, where women constituted 28.7% of directors at the
Smith also pointed to previous research her group has conducted into primarily masculine attributes that entertainment industry professionals ascribe to directors.
"The way the role is conceived is, a director has to be aggressive, like a general leading troops into battle," Smith said.
In addition to issues of prevalence, the study also looked at how gender influences the way characters are presented on-screen, finding female characters much likelier to be sexualized than male ones. More than 30% of females were portrayed in tight or revealing clothing versus 9.7% of males, while 29.5% of females were shown with full or partial nudity versus 11.7% of males.
One factor that influenced those portrayals was who was behind the camera: Films with at least one female producer were 10.6% less likely to depict female characters partially or fully naked than were films with no female producers attached, researchers found.