Men’s Advantages in Spatial Cognition & Mechanical Reasoning

As I mentioned in a recent post, "Women’s Advantages in Social Cognition," we anticipate nuance in the pattern of cognitive sex differences and in the supporting brain systems. Broadly speaking, evolved cognitive abilities (e.g., language) and biases (e.g., favorable evaluations of members of the in-group and unfavorable evaluations of members of competing out-groups) can be organized around the domains of folk psychology (abilities and knowledge related to the self and other people), folk biology (knowledge focused on other species), and folk physics (abilities and knowledge focused on the physical world).

In the previous post, I described girls’ and women’s advantages in aspects of social cognition that support the development and maintenance of interpersonal relationships and that undergird relational aggression (e.g., sensitivity to subtle facial expressions).

Here, I focus on men’s advantages in aspects of folk physics. At the broadest level, folk physics is composed of abilities and biases that support movement in space (e.g., navigation), the mental representation of images and generation of cognitive maps, and an implicit understanding of how objects can be used as tools, or more generally mechanical reasoning. Boys and men have small-to-rather-large advantages in these areas, depending on the complexity of the task. I cannot discuss all of these differences but will illustrate them with a few examples.

By movement, I mean not only the ability to navigate in novel terrain but also general sensitivity to large-scale space, and the ability to detect, track, and intercept objects moving in space. These latter abilities are consistent with an evolutionarily elaboration of the brain and cognitive systems that support men’s use of and protection from projectile weapons. In support of this interpretation, the sex differences in the skeletal structure of the upper body and upper-body strength are highly consistent with an evolutionary history of male-male competition that involved the use of blunt force (e.g., axes) and projectile (e.g., rocks, spears) weapons.

The use of projectile weapons requires the ability to accurately throw objects at moving targets that in turn requires systems that enable men to estimate the motion of objects moving in space and that provide an intuitive understanding of when one object will intercept another one.

For instance, Law, Pellegrino, and Hunt (1993) found no sex differences in the ability to judge which of two objects had traveled farther, although men are generally better in estimating distances longer than those assessed by Law et al. In any case, they did find that men have moderate to large advantages in the ability to judge object velocity. In one of the studies, they found that more than 4 out of 5 men were more sensitive to relative velocity than was the average woman. Practice and feedback improved the performance of both sexes, but the magnitude of men’s advantage did not change.

Boys and men have corresponding advantages in throwing distance, velocity, and accuracy. Jardine and Martin (1983) provided an early demonstration of this sex difference when they found that about 7 out of 8 adolescent boys threw more accurately at a non-moving object than did the average same-age girl, whereas 9 out of 10 of their fathers threw more accurately than their mothers. The same sex difference is found in the Hadza, a traditional hunter-gatherer society in Tanzania. To control for men’s greater experience in the use of bows, Cashdan and colleagues (2012) asked men and women to throw beanbags underhanded at targets that were 4 to 9 meters away. This is a very easy task compared to actual combat with projectile weapons or their use in hunting. Despite the ease of the task, 8 to more than 9 out of 10 men were more accurate in their throws than was the average woman, depending on distance.

These sex differences are often attributed to the sexual division of labor, in particular men’s hunting. It is certainly the case that men’s hunting is an important source of food and confers status on skilled hunters in traditional contexts; these men are preferred as mates and often have more surviving children than do less skilled hunters.

On the other hand, the sex differences in overall physical size and likely upper body strength is evident in australopithecines (dating back at least 4 million years) who, based on teeth architecture and other traits, were not big-time meat eaters; the physical sex differences attributed to the sexual division of labor were evident long before our ancestors hunted for meat. Moreover, boys and men also have substantial advantages in the ability to track and block objects thrown at them. Hunted game don’t typically throw objects at their pursuers, but other men do. In other words, the sex difference in blocking skill is consistent with an evolved defensive system to avoid being hit by projectiles.

Hunting as well as negotiating relationships with neighboring villages (e.g., politically or to raid them) often requires distant travel in novel terrain and men engage in much more of this than women. Across traditional societies, MacDonald and Hewlett (1999) reported that men traveled roughly 2 to 4 times farther than women during their typical ranging activities. Ecuyer-Dab and Robert (2004) found the same for women and men in Montreal, where men’s personal travel range was 1.8 times larger than women’s range. In other species in which males have larger ranges than females, males are better at navigating and at various experimental maze tasks than are same-species females.

The same is true for people. Boys and men generate cognitive bird's-eye-view maps of the habitats in which they are traveling more quickly than do girls and women and have advantages in a number of related areas (e.g., understanding maps). The magnitude of these sex differences varies with age, task complexity, and experience in exploring the environment, with the largest differences after adolescence and after some spatial experiences.

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Some of the spatial abilities in which boys and men have an advantage appear to contribute to the ability to visualize how objects might be used as tools and are likely important in the construction of tools. More abstractly, the latter is the basis for mechanical reasoning. Boys and men report more interest in mechanical objects and how they work, and there are large sex differences on complex mechanical reasoning tasks in adolescence and adulthood. Here, about 4 out 5 boys and men score higher on complex mechanical reasoning tasks than do same-age girls and women, although the sex difference is small for less complex tasks.

Across this post and the last one, we see that girls and women have advantages in understanding and navigating the nuances of interpersonal relationships, whereas boys and men have advantages in understanding, manipulating, and understanding the physical world. In a later post, I’ll discuss how these differences are expressed in modern contexts (e.g., occupational choices).