There are remarkably few stable sex differences in cognitive abilities. On average, men and women tend to perform similarly on a wide range of abilities. In addition, the variability in performance across men and women tends to be much larger than any observed differences in average performance. So, even when a study finds a difference in average performance, that difference pales in comparison to other individual differences that affect performance.
One ability that has shown consistent sex differences, though, involves spatial perspective taking. Suppose, for example, that you are looking at a map of a city. You are trying to plan a route to walk from one building to another. If you hold the map oriented north, then as you walk, you have to imagine whether you turn right or left at each intersection. Because the way you are holding the map does not always match how you would be facing at that intersection, it can be difficult to judge whether you are making a right or a left turn at that particular intersection. Many studies suggest that (on average) men perform tasks like this better than women.
It is less clear why there is this sex difference. It is easy for researchers to tell stories about the evolutionary advantage of better spatial abilities for men than for women. For example, if men were more likely to be hunters in our evolutionary history, then it might make sense for them to have spatial abilities that would allow them to track and capture prey.
Before weaving an elaborate story like that, though, it is important to ensure that the differences observed on tasks reflect differences in ability. It is also possible that something about the way studies are done leads to systematic differences between men and women.
This question was explored in a paper in the November, 2016 issue of Psychological Science by Margaret Tarampi, Nahal Heydari, and Mary Hegarty.
They suggested that two aspects of spatial ability tasks may favor men over women. First, there is a broad cultural belief that men are better at spatial tasks than women. Research on stereotype threat suggests that when people believe that they should be bad at a task, it makes them perform worse on that task than when they do not have that belief. It is possible that women perform worse than men on spatial ability tasks because of this stereotype threat.
Second, most spatial ability tasks are done using abstract materials like maps or configurations of random objects. Another possibility is that women are best in spatial reasoning tasks when there is a social component to them, such as when one person has to give directions to another or to imagine what another person would see in a situation.
The researchers in this study tested both possibilities. They tested men and women in two types of spatial reasoning tasks. One involved having people imagine whether they would turn right or left when following a route on a map. The second involved imagining themselves in a scene that they could see from an overhead perspective. They had to imagine facing in a particular direction and then point to where other objects in that scene would be.
In the first study, the researchers gave instructions that did or did not promote stereotype threat. One set of instructions told people that men usually do better on tests of spatial reasoning than women. The other set of instructions suggested that women are better than men at many social tasks and that taking another perspective is often a social task. In addition, the materials for the study either used maps and random objects or they also included people in the materials. In the map task, the person task had a figure of a person at each intersection oriented in the direction of travel. In the overhead perspective task, people had to take the perspective of a person facing in a particular direction in the scene.
In this study, men did better than women when the instructions suggested that men are better than women at social tasks and also when the materials did not have people in them. When the instructions suggested that women are good at social tasks and the materials had people in them, then they did just as well as the men. Two followup studies suggested that both the instructions and the presence of people in the materials improved the performance of women on the task.
These findings suggest that observed differences between men and women in tests of spatial orientation do not reflect differences in an underlying ability. Instead, when the task is presented abstractly, a combination of stereotype threat and the lack of an obvious social component to the task biases the task in favor of men. When the task is presented in a social context either through the instructions or the materials, then men and women perform equally well.
This work also demonstrates how hard it is to interpret studies that find sex differences in performance. It is tempting to interpret these studies as a reflection of differences in ability. However, it is challenging to rule out that the sex differences reflect something about the way the task is carried out rather than the ability required to perform the task.
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Tarampi, M.R., Heydari, N., & Hegarty, M. (2016). A tale of two types of perspective taking: Sex differences in spatial ability. Psychological Science, 27(11), 1507-1516.