In one study, 30 children17 boys and 13 girls aged between 3 months to 8 months (at this age, they don’t yet identify with genders) were shown a doll and a truck for two 10-second intervals.
Eye-tracking technology was then used to measure how many times and for how long the babies focused on each object.
The study found that girls showed a visual preference for the doll and the boys for the truck.
Similar experiments were conducted with monkeys and it was found that male adolescent monkeys preferred to play with wheeled vehicles while the females preferred dolls.
When researchers exposed female monkeys to male hormones before birth, these females later displayed male-like preferences.
Similar results are found in human beings — Congenital Adrenal Hyperplasia (CAH) is a genetic condition that results when the female foetus is subjected to large quantities of male hormones.
Girls with CAH were found to prefer trucks & cars, etc. over dolls and play tea-sets.
In another experiment, it was found that the higher the testosterone levels in 3- and 4-month-old boys, the higher their visual preference for male-typical toys.
Based on evidence from such studies, researchers conclude that the foetus’ exposure to the hormones in the womb is responsible for gender-based toy preferences.
On why testosterone (the male hormone) would increase preference for male-typical toys is still not known.
However, there is another school of thought, which claims that it is the socialisation and marketing that has led the boys and girls to prefer one kind of toys over the others.
The proponents of this theory suggest that it was after WWII, when pink became the colour for girls, that manufacturers caught on to the idea that they could sell more if toys for boys & girls were separated.
E.g., you can’t pass the pink clothes or dolls of your now-7-years-old daughter to your 3-years-old son.
Another argument for this being a marketing & societal thing is that while a 1-year-old boy may still choose a doll over a truck but a 3-year-old boy will almost never do that.
This is because, by age 3, this boy would have been exposed to marketing and corrected many times by parents/relatives for displaying any ‘non-boyish’ behaviour.
