Nature v. Nurture: Primates and their Playthings
The controversy of late regarding the gendering of children’s toys has spawned a new article by science blogger Paul F. Norris and published on iO9.com that is intended to “shed light on the nature/nurture debate over gender identity” regarding toys, by tackling the issue of gender differences as innate and biological, or arising out of society and environment. To do so, Norris uses two older studies done on primates (rhesus monkeys and chimpanzees) and their playthings.
It’s Nature
Findings from a 2009 study at the Yerkes National Primate Center at Emory University determined that “male” rhesus monkeys prefer “wheeled toys” traditionally reserved for human “boys,” while “female” monkeys in the studies varied their preferences between “plush” toys (i.e. dolls, stuffed animals) and wheeled toys.
Norris states in the article that these are similar tendencies found in humans and thus the primate center researchers decided that “distinct male and female toy preferences can arise in the absence of socialization pressures and hypothesized that there are hormonally organized preferences for specific activities that shape preference for toys that facilitate these activities.”
It’s Nurture
Next, Norris revisits a paper published in 2010 by Sonya Kahlenberg of Bates College and Richard Wrangham of Harvard University who present the first evidence of wild male and female primates, chimpanzees (Pan troglodytes) in the Kanyawara chimpanzee community of Kibale National Park, Uganda, interacting differently with play objects.
“Over a 14 year period, Kahlenberg and Wrangham observed that juvenile Kanyawara chimpanzees tended to carry sticks in a manner suggestive of rudimentary doll play and that the behavior was more common in females than in males. Juvenile chimps, particularly females, would carry around small sticks for hours at time while they engaged in other daily activities such as eating, climbing, sleeping, resting and walking. While the same chimps used sticks as tools for specific purposes, the researchers were unable to discern any practical reason for the stick-carrying. This chart shows the degree to which female chimps were more likely to engage in the stick carrying behavior.”
“The researchers theorized that the link was related to infant care, or “maternal play.” And also suggested a social rather than biological basis for the behavior. Because regular stick-carrying hasn’t been reported in other wild chimpanzee communities, they proposed that that young Kanyawara chimpanzees may be learning the behavior from each other as a way of practicing for adult roles – a form of social tradition passed between juveniles previously described only in humans. Kahlenberg and Wrangham conclude by noting that: Our findings suggest that a similar sex difference could have occurred in the human and pre-human lineage at least since our common ancestry with chimpanzees, well before direct socialization became an important influence”
Clueless
As such, Norris provides no actual hypothesis themself, but instead, supposes that nobody really has any clue at all.














