Male and Female Monkeys Also Choose Different Toys

Throughout the world, boys and girls prefer to play with different types of toys. Boys typically like to play with cars and trucks, while girls typically choose to play with dolls. Why is this? A traditional sociological explanation is that boys and girls are socialized and encouraged to play with different types of toys by their parents, peers, and the “society.” Growing scientific evidence suggests, however, that boys’ and girls’ toy preferences may have a biological origin.

In 2002, Gerianne M. Alexander of Texas A&M University and Melissa Hines of City University in London stunned the scientific world by showing that vervet monkeys showed the same sex-typical toy preferences as humans. In an incredibly ingenious study, published in Evolution and Human Behavior, Alexander and Hines gave two stereotypically masculine toys (a ball and a police car), two stereotypically feminine toys (a soft doll and a cooking pot), and two neutral toys (a picture book and a stuffed dog) to 44 male and 44 female vervet monkeys. They then assessed the monkeys’ preference for each toy by measuring how much time they spent with each. Their data demonstrated that male vervet monkeys showed significantly greater interest in the masculine toys, and the female vervet monkeys showed significantly greater interest in the feminine toys. The two sexes did not differ in their preference for the neutral toys.

...how can these male and female vervet monkeys have the same preferences as boys and girls? They were never socialized by humans, and they had never seen these toys before in their lives. Yet, not only did male and female vervet monkeys show the identical sex preference for toys, but how they played with these toys was also identical to how boys and girls might.

In a forthcoming article in Hormones and Behavior, Janice M. Hassett, Erin R. Siebert, and Kim Wallen, of Emory University, replicate the sex preferences in toys among members of another primate species (rhesus monkeys). Their study shows that, when given a choice between stereotypically male “wheeled toys” (such as a wagon, a truck, and a car) and stereotypically female “plush toys” (such as Winnie the Pooh, Raggedy Ann, and a koala bear hand puppet), male rhesus monkeys show strong and significant preference for the masculine toys.

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