The gender biases that shape our brains

These initial divisions may seem innocent, but over time our gendered worlds have lasting effects on how children grow up to understand themselves and the choices they make – as well as how to behave in the society they inhabit. Later, gendered ideas continue to influence and perpetuate a society which unknowingly promotes values linked to toxic masculinity, which is bad news for all of us, however we identify. So how exactly does our obsession with gender have such a lasting impact on our world? The idea that women were intellectually inferior to men was regarded as fact several centuries ago. Science has long sought to find the differences that underlined this assumption. Slowly, numerous studies have now debunked many of these proposed differences, and yet our world remains stubbornly gendered.

When you think about it, this is wholly unsurprising due to the way we are socialised as infants. Parents and caregivers don't mean to treat boys and girls differently, but evidence shows they clearly do. It starts before birth, with mothers describing their baby's movements differently if they know they are having a boy. Male babies were more likely to be described as “vigorous” and “strong”, but there was no such difference when mothers did not know the sex.

Ever since it was possible to identify biological sex from a scan, one of the first questions asked of prospective parents is whether they are having a boy or a girl. Before then, the shape and size of a bump has been used to guess the sex, despite there being no evidence this works. More subtle are the different words we use to describe boys and girls, even for the exact same behaviour. Throw gendered toys into the mix and this reinforces the subtle traits and hobbies that are already assigned to male and female.

The way children play is a hugely important part of development. It's how children first develop skills and interests. Blocks encourage building whereas dolls can encourage perspective taking and caregiving. A range of play experiences is clearly important. “When you only funnel one type of skill building toys to half of the population, it means that half of the population are going to be the ones developing a certain set of skills or developing a certain set of interests,” says Christia Brown, a professor of psychology at the University of Kentucky.

Children are also like little detectives, working out what category they belong to by constantly learning from those around them. As soon as they understand what gender they fit into, they will naturally gravitate towards the categories that have been thrust upon them from birth. That's why from the age of about two, girls tend to navigate more to pink things while boys will avoid them. I witnessed this first-hand when my then two-year old stubbornly refused to wear anything she perceived as slightly boyish, despite my futile attempts not to overtly gender her clothing early on.

It's no surprise then that pre-school children learn to identify with their gender so young, especially as parents and friends tend to give children toys associated with their gender early on. Once children understand which “gender tribe” they belong to, they become more responsive to gender labels, explains Cordelia Fine, a psychologist at the University of Melbourne. This then influences their behaviour. For instance, even how a toy is presented can change a child's interest in it. Girls have been found to be more interested in typically boyish toys if they were pink, for instance.

This has consequences though. If we only give girls and not boys dolls or beauty sets, it primes them to associate themselves with these interests. Boys can be primed to like more active pursuits by toy tools and cars.

Yet boys clearly enjoy playing with dolls and buggies too, but these are not as typically bought for them. My son cradles a toy baby just as his sister did and likes to push it around in a toy buggy. “Boys in the first years of life are also nurturing and caring. We just teach them really early that that's a 'girl skill', and we punish boys for doing it,” says Brown.

If from infancy, boys are discouraged from playing with toys we might associate as feminine, then they may not develop a skill set that they might need later in life. If they are discouraged by their peers from playing with dolls, while at the same time they see their mother doing most of the childcare, what does that say about whose role it is to care? And so we enter the realm of “biological essentialism”, where we ascribe an innate basis to a behaviour that is, when you delve a bit deeper, highly likely to be learned.

Toys are one thing, but traits are also prone to gendered stereotyping. Parents of boys often talk about how they are more boisterous and enjoy rougher play, while girls are more gentle and meek. The evidence suggests otherwise.

In fact, studies show that our own expectations tend to frame how we view others and ourselves. Parents have attributed gender neutral angry faces as boys while happy and sad faces are labelled as girls. Mothers are more likely to emphasise their boys' physical attributes – even setting more adventurous targets for boys than for girls. They also over-estimate crawling abilities for their sons compared to daughters, despite there being no reported physical difference. So, people's own biases could be influencing their children, and so reinforcing these stereotypes.

Language plays a powerful role too – girls reportedly speak earlier, a small but identifiable effect but this could be due to the fact that research also shows that mothers speak more to their baby girls than to baby boys. They speak more about emotions to girls too. In other words, we unknowingly socialise girls to believe they are more talkative and emotional, and boys aggressive and physical.

Brown explains that it's clear why these misconceptions then continue later in life. We disregard the behaviours that do not conform to the stereotypes we expect. “So you overlook all the times the boys are sitting there quietly reading a book or all the times that girls are running around the house loudly,” she says. “Our brains seem to skip over what we call stereotype inconsistent information.”