Professor Kim Wallen and his colleagues at the Yerkes National Primate Research Center in Atlanta decided to do this familiar study again, with a little twist: instead of offering human children a choice between dolls and trucks, they gave that choice to monkeys. They gave monkey the opportunity to play with a “boy toy” such as a truck or with a “girl toy” such as a doll.
The basic pattern of results was similar to the pattern seen with human children. The female monkeys slightly prefer to play with dolls rather than trucks. The males substantially prefer to play with trucks rather than dolls.
It is difficult to invoke the social construction of gender to accommodate this finding. You would have to assert that a monkey in authority, maybe a parent, is saying to a young male monkey, Don’t let me catch you playing with a doll! But in fact nothing of the sort happens. Monkeys don’t appear to care whether other monkeys, female or male, are playing with trucks or with dolls. And yet the main effect – the preference of the male to play with a truck rather than with a doll – is clearly present in monkeys, as it is in human children. But the social construction of gender cannot reasonably be invoked to explain this effect in humans, in view of the fact that a similar effect is present in monkeys…
Developmental psychologist Gerianne Alexander found sex differences among monkeys similar to the sex difference we see among human children. In 2003, one year after she published her monkey study. Professor Alexander published her theory explaining why female and male monkeys – as well as female and male humans – might prefer to play with different toys.
Scientists have known for more than thirty years that our visual system is actually two separate systems operating in parallel, beginning at the level of the ganglion cells in the retina and extending back to the visual cortex and visual association cortex. One system is devoted to answering the question What is it? What’s its color? What’s its texture? The other system is devoted to answering the question Where is it going? And how fast is it moving? These two systems in the brain are often referred to as the “what” and the “where” system.
Professor Alexander was the first to suggest that hardwired sex differences in the visual system may explain finding such as the observed sex difference is the toy preferences of children (as well as monkeys). She conjectured that maybe girls have more resources in the “what” system, while boys have more resources in the “where” system. Girls are more likely to play with a doll rather than with a dull gray truck because the doll has a more interesting color and texture. Boys are more likely to play with the dull gray truck because it has wheels. It moves.
Professor Alexander’s hypothesis helps to make sense of many finding that otherwise are hard to explain. For example, baby girls (three to eight months of age), but not baby boys of the same age, prefer to look at dolls rather than at toy trucks. When researchers show women and men different colors and ask them to name the colors, “women respond faster and more accurately than men.” When researchers test men and women to see how accurately they can target a moving object, men are significantly more accurate than women… Finally researchers in Germany have reported dramatic sex differences in the anatomy of the human visual cortex in adults, with significantly more resources devoted to the “where” system in men that in women, even after adjusting for any overall size difference in the brain.
Leonard Sax – Why Gender Matters p.327