A pink truck is still a truck

When you walk into any baby store, it quickly becomes obvious that boys like blue trucks and girls like pink dolls. You might find a yellow pajama with a puppy on it, but that one is probably intended for the pregnant mom who doesn’t want to find out the sex of her baby but wants to buy a pajama. Many researchers have speculated on why boys and girls like different colors and different toys. There are three main theories out there. The first one, the “social learning” theory, suggests that children like certain toys and colors because they are socialized to like them: they like the toys their parents buy for them. The second theory, the “cognitive theory”, suggests that a child knows what gender he or she is, and is aware of the stereotypes, so he or she chooses accordingly. Finally, the “hormonal theory” suggests that sex differences in the prenatal hormone environment changes how the brain organizes itself and leads to female- or male-typed behaviours. For example, high levels of androgen (the male hormone) lead to brain masculinization and the choosing of trucks over dolls. While this may sound crazy, experiments have shown that female fetuses exposed to abnormally high androgen concentrations spend more time playing with masculine toys compared to regular girls. To make things even more complicated, studies have shown that some kinds of monkeys also show sex-specific toy preferences (and Daddy Monkey doesn’t shop at Wal-Mart, so there goes the “social learning” theory). So, is it already in your brain when you’re born, or do you learn to love blue trucks or pink dolls?

Researchers set out to shed some light on this question by studying 120 boys and girls aged 12 to 24 months. The task was very simple: the child was shown two images simultaneously (for example, a red car and a red doll, or a blue car and a pink car), and a camera recorded how long the child looked at each image, which is a measure of interest.

The researchers found that boys preferred cars and girls preferred dolls. No big surprise there. Unfortunately, because children 12 months old or older have already been provided with sex-typed toys, their looking preference may reflect the types of toys they have at home and the researchers could not draw any conclusions on whether this behavior was learned or innate.

The interesting finding lies in the colors: as it turns out, the children cared very little about the color of the images. Boys preferred the cars, regardless of whether they were pink or blue, and conversely, girls preferred the dolls, regardless of their color. In fact, the researchers found that as a whole, everybody liked red the most. This finding indicates that the stereotypical color preferences seen in older children are most likely learned behaviours.

As I’ve mentioned before, my favorite kind of research article is the one that leaves me with more questions than I started with, and this is one of them. Why was pink adopted as the “girl” color if girls aren’t naturally drawn to it? At what stage does the shift occur from not caring about colors to caring about them? Is this shift really purely socially driven? In any case, the next pajama I buy for a child will be red.

Reference: Infant’s preferences for toys, colors and shapes: sex differences and similarities. Jadva, V. et al. Arch Sex Behav [Epub ahead of print] (2010).