PROVIDENCE, R.I. — A 13-year-old girl's campaign to get Hasbro to make an Easy-Bake Oven that isn't purple or pink so it would appeal to her little brother is a fresh sign of movement in an old debate. Parents who hope to expose their children to different kinds of play -- science sets for girls and dolls for boys, for example -- can find themselves stymied by a toy industry that can seem stuck in the past when it comes to gender roles.

Hasbro wasn't the only target of criticism this year.

One of the year's hottest toys, the "LEGO Friends Butterfly Beauty Shop," specifically aimed Legos at girls, but turned to tired gender stereotypes with its focus on a beauty shop and inclusion of characters with curves and eyelashes. Barbie turned builder with a new construction set. But while some praised it, others criticized it for being too pink.

Toy experts say the industry reflects cultural norms, and toy companies are giving people what sells. Plenty of parents find nothing wrong with buying pink frou-frou toys for their girls and avoiding stereotypically "girl" toys for their boys in favor of guns and trucks. But other parents are sent into knots by an unapologetically gender-specific toy industry.

"There's a lot of pressure to conform to those gender stereotypes from the time you're pregnant," said Teresa Graham Brett, a higher-education consultant from Tucson, Ariz., and mother to two boys, ages 6 and 11.

Children naturally begin to identify themselves as boys and girls around the ages of 3 and 4, said Dr. Susan Linn, a psychologist at Harvard Medical School, who cofounded the advocacy group Campaign for a Commercial-Free Childhood.

"When a child's environment is filled with rigid messages about, ÔThis is what boys do, this is what girls do,' it limits their ability to reach their full capacity," Linn said. "It's not like girls are born with the predilection to pink, but they're trained to it, so it becomes what they want and need. There are neurological differences between boys and girls at birth. But our goal should be to provide them with a range of experiences so they can develop all of their tendencies."

Large toy stores and most large online retailers often divide toys up by gender. On Amazon, or on the websites for toy makers Mattel or Hasbro, for example, toys are sorted by age, category and gender. A person who wants to buy a baby doll on the Toys R Us website will find hundreds of choices categorized for girls and five for boys. Three of those are dressed in pink.

In recent years, Toys R Us was criticized for an ad selling three microscopes, silver, red and pink. The pink one was the least powerful.

"Toy companies are businesses, so they are responding to and making their products based on consumer demands. They're meeting with moms, focus groups. They're doing what makes sense," said Adrienne Appell, a spokeswoman for the Toy Industry Association.

Chris Byrne, content director for timetoplaymag.com, said the market ultimately decides what makes it onto store shelves and into people's homes.

"The toy industry is always going to reflect the culture at large, and it's going to reflect the market," he said.

That's even true for a soon-to-be-released toy that has gotten a lot of attention for seeking to subvert gender stereotypes. GoldieBlox, a construction toy, was invented by Debbie Sterling, who holds a degree from Stanford in product design engineering and who aimed to make a toy to spark an interest in girls in science and engineering. She was turned off by what she saw in a visit to a toy store.

"I felt like I was in the 1950s," she said. "The girls section was pink. It was teaching a girl how to be a housewife, and a princess and pop star."

Meanwhile, she described the boys section as dynamic, with kits to make interesting things like roller coasters and "smarter more complex, engineering math and science toys."

The toy's main character is Goldie, a female engineer, and it is scheduled to be on store shelves in April. In a concession to commercial realities, the toy's color scheme includes a liberal dose of pink.

"There's a lot of parents out there, they're conditioned by this. They won't even pick up something if it doesn't cue that it's a girl," she said. "I don't want girls to miss out on GoldieBlox because it wasn't overtly messaged for them, at least in the early stages."

Some things are changing in the industry. This year, the London department store Harrods redesigned its toy department to organize it by theme rather than by gender. Swedish toy firm Top-Toy published a gender-neutral catalog in which boys were shown playing with a kitchen set and hair dryer and a girl was shown shooting a toy gun.

Hasbro this week announced it has spent the past 18 months developing an Easy-Bake Oven in the gender-neutral colors of black and silver. It made the announcement after meeting with McKenna Pope, the Garfield, N.J., 13-year-old whose online petition asking the company to make one attractive to all kids gathered tens of thousands of signatures. Hasbro says it knows both boys and girls have fun playing with the Easy-Bake.

Even parents who are sensitive to gender issues say they sometimes have to challenge their own notions. Brett said her older son was interested in toys aimed at both genders as a little boy. But when son number two came along five years later, she was surprised to see he had a stronger preference to play with guns and Army men.

"I really needed to let go of controlling what I thought he should play with as an enlightened boy," she said. "They may choose to do what is stereotypical, and they should have the right to choose that as well."