At five preschools in Stockholm you won’t find the usual designated areas for dressing up, building blocks, toy cars and dolls houses. All the toys are purposefully jumbled up together as part of a gender-neutral policy.

The concept began in 1998 when an amendment to Sweden’s Education Act stipulated that all schools must work against gender stereotyping. As a result, Lotta Rajalin, the head of five state preschools for children aged one to six, introduced gender-neutral policies in her preschools. In 2011 she opened Egalia (equality in Latin), a school that specialises in gender equal teaching – an approach that does not assume that different genders have different characteristics, wants and needs. “It’s all about democracy,” says Rajalin. “We want to give all children the same opportunities the same rights.”

“We don’t say, ‘Come on boys, let’s go and play football,’ because there might be girls who want to play football,” says Frida Wikström, the schools’ coordinator. “We say ‘friends’ instead because it puts yourself on an equal level.”

The children can use whatever language they like but if one of them says something like: “You can’t play that, it’s a boys’ game,” the teachers use open questions to discuss why the child feels like that. They use “hen” as a gender neutral alternative to he or she because they feel that it discourages stereotyping. “For example, if a firefighter is coming in and we don’t know if they are a man or woman we would call them ‘hen’,” says Wikström. “We assume it’s a ‘he’ because we get that image in our head.” They also use “hen” in songs where they’ve noticed that more assertive or aggressive animals tend to be called “he” and sweeter ones “she”. “A bear is nearly always a he. Why is that?” asks Wikström.

When Rajalin started out, she filmed teachers to see if how they treated boys and girls varied. “We discovered that there is a big difference,” says Wikström. “For example, we would take a lot more time to comfort girls. Boys were just told, ‘Off you go, you’re fine.’”

The next step was developing guidelines. They include not assuming that different genders play in a certain way. For example, the building blocks, cars, dolls and dressing-up play areas are mixed together, opening up more interaction between the boys and girls.

“It’s had a really positive effect. Boys and girls play a lot more together. It’s very rare that you hear a boy say, ‘I only want to play with boys’. It’s important to us to really work on the idea that we’re friends and a group, not separated by gender.”

It’s not all been smooth sailing, however most of the challenges have come from adults. First, changing deeply-ingrained attitudes to gender from staff is not easy, says Wikström. “We assume we treat everyone the same, but we don’t,” she says. “It’s very difficult to change behaviour.” Asking staff to analyse their behaviour has also been difficult. “To look at oneself in a critical way is not always that pleasant, but that is the starting point.”

The schools have a policy of recruiting staff members with a diverse range of backgrounds, from 20-year-old Swedish women just out of university to a 50-year-old man from Iran (they have a much higher proportion, about 40%, of male teachers compared with other schools). The staff members have a lot of discussion and training, and they all agree on the guidelines before they start.

Although some parents chose the schools specifically for their gender-neutral policies, accepting the approach can be challenging for others. The staff show parents a circle separated into two with gender stereotypes in each half. “We explain, ‘Do you want your child to have half a life or a whole life?’” says Wikström. “Everyone wants the most for their children. Even fairly traditional parents get it when they see that it’s not about taking anything away from the child.”

Spaces where children can be whatever they want to be are important, says Pippa Hodges, a child counsellor at schools in north London. But there could also be risks with a gender-neutral environment. “There might be a danger of children identifying strongly with a particular gender and not being supported in that; the risk of confusion and shame is high at this developmental stage,” she explains.

Genevieve Passamonte, a nursery school teacher in north London, also has her reservations: “Every good nursery has equal opportunities and anti-bias policies. It’s absolutely fine if a little boy wants to wear a dress, but... it’s important for the children to learn language correctly.”

Neuroscientist and director of educational space Science Gallery, Daniel Glaser, says studies support the idea that language is vital to defining behaviour. “Very subtle changes in language can have dramatic effects,” he says. “Psycholinguistics, or the use of different words, is very influential on teachers’ behaviour.”

It will also be vital for changing children’s perceptions. “If you think that the way that children perceive gender is important, then making an early intervention to equalise between the genders is a good idea. It’s definitely too late by the time they get older,” he adds.

Ideas of how each gender should behave are also becoming less rigid with each new generation. Hodges says children and young people are far more accepting of the fluidity of gender and sexuality than older generations.

Rajalin describes her school’s approach as preparing children for this new world. “We must work against our traditional way of thinking,” she says. “The world that I grew up in doesn’t exist anymore. The children are going to be adults in 15 or 20 years’ time. They are going to live in another sort of society. We have to prepare them for that.”

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