Two researchers from the University of Hong Kong suggest that toymakers and parents avoid gender-labelling toys, remove colour divides, and manufacture toys for both boys and girls in a wide range of colours. Sui Ping Yeung and Wang Ivy Wong's study is published in Springer's journal Sex Roles, and shows how easily preschoolers' ideas about what is appropriate for their gender is manipulated. Their study is also the first to show that a boy's preference for blue and a girl's liking of pink is not just a Western construct, but is also a phenomenon in urban Asian societies.

The researchers recruited 129 preschool Chinese children aged between five and seven from two kindergartens in Hong Kong. First the researchers assessed the children's preference for pink versus blue by showing them cards and toys in these colours. Then the children were presented with yellow and green cards and toys. They were randomly divided into so-called label and no-label groups.

Children in the no-label group were presented with coloured cards and toys which had no reference to a specific gender and these children consequently expressed no preference for a specific colour. However, preschoolers in the label group were told that yellow was a girl's colour and green a boys' colour, and corresponding gender differences emerged in the choices they made.

Apart from randomly assigning children to these two groups, the children's pre-existing preferences for yellow and green were statistically controlled, so the resulting difference between the groups speaks strongly to a causal effect of the gender labels.

According to the researchers, the gender differences between preferred colours in children is noteworthy because it is so much more prominent than most other psychological differences between the sexes.

"Our findings support the notion that gender-typed liking for pink versus blue is a particularly salient gender difference," explains Yeung. "Moreover, our findings reveal that gender differences could be created merely by applying gender labels."

"By applying gender labels, not only concrete materials such as toys could become gender-typed, but also abstract qualities such as colours, with children increasing or decreasing their likings for particular colours based on the gender labels available in their social environment," Wong says.

The findings support previous research that highlighted the strong influence that gender labels such as "for boys" or "for girls" might have. Further, the observations are in line with gender schema theory that says that once children have learnt a specific gender identity, their behaviour will be guided by the standards set as being appropriate for their specific sex. These will guide them later in life on how they interact and adapt to their surroundings, for instance, when taking on chores around the house, such as cooking, cleaning or repairing things.

Wong also commented on the cultural angle of this study: "Many gender differences and stereotypes in developed Asian regions resemble those in the West, which is not surprising given the high degree of Westernization and the prevalence of gender colour-coding typical of Western cultures in Hong Kong."

The study also goes beyond investigating why boys and girls prefer different colours. The researchers also tested whether using gender-coded colours in toys affects how well children play. The children were given yellow and green puzzles to play with. Whether the puzzles were in the gender appropriate or gender inappropriate colour did not make a difference in the children's puzzle performance.

However, the researchers caution against using this finding to support the use of gender-coded colours to increase sales. The results showed that boys and girls performed equally well but if they had been exposed to gender labels, regardless of whether they received the gender appropriate or gender inappropriate coloured puzzles, a gender difference emerged, with boys outperforming girls.