The children's television show Thomas the Tank Engine does not present strong female characters, an analysis by a University of Alberta professor found.

The children's television show Thomas the Tank Engine pushes a conservative ideology and relegates female characters to the back of the train — literally — concludes a study by a University of Alberta professor.

Political studies professor Shauna Wilton came to that conclusion after watching 23 episodes of Thomas with her three-year-old daughter.

Several aspects of the show, which airs on Treehouse and PBS in the U.S., bothered Wilton, including the strict hierarchy of characters and the constant effort of everyone to please the railroad boss.

"There's a really clear social hierarchy, and everyone is looking down at the characters that are below them, and generally speaking, the political outlook is pretty conservative," Wilton said Monday in an interview with CBC Radio's As It Happens.

Wilton was intrigued by the role of the railway boss, Sir Topham Hat, who wears a black suit and a top hat.

"The best thing that can happen to a train is to be praised by Sir Topham Hat, and the worst thing that can happen is for him to be disappointed in them," she said.

She noted that characters are discouraged from "thinking outside the box" or from trying to express an independent point of view. But what bothered her the most were the roles assigned to females.

The steam engines were at the top of the hierarchy, and they looked down on the "dirty diesel engines," and everyone looked down at the cars that were pulled by the engines, which are mostly female characters.

"The gender roles were particularly interesting to me because I have a daughter who watches the show, and as the mother of a daughter, I want her to be watching shows with strong female characters in them. And female characters are pretty much confined to supporting roles in this show," said Wilton.

"Thomas has Annie and Clarabel. They chug along behind him and repeat what he says and cheer him on or express concern and worry if they don't feel he's doing the right thing."

Wilton said she recognizes the show is for children but says that is no reason not to view it critically since television plays an important role in children's lives. Statistics Canada says the average Canadian child watches 14 hours of TV per week, and some early childhood experts believe TV plays an integral role in how children are socialized.

"As political scientists, we need to be thinking critically about it and not assume that just because it's television for kids, there's nothing in it," said Wilton. "We need to look at it a little more deeply and be a little more critical."

Her study, which has garnered news coverage in the U.K. and Australia, hasn't affected how often she lets her daughter watch the show.

"My daughter loves Thomas, and even if some of the episodes don't portray my personal values, I still let her watch them, and we just talk about it a bit," she said.