Information-processing centres in the brain are based on grey matter while the connections between these centres are made by white matter. These differences could explain why some men are very good at some tasks, such as mathematics, which require more local information processing, while some women tend to excel at language which it is claimed uses white matter to integrate and assimilate information from the various grey-matter regions in the brain that are required for language. Most grey-matter regions and white-matter regions involved with intellectual activity in women are in the frontal lobes, compared to very much less in males, where the relevant grey matter is distributed throughout more of the brain. The fact that if a woman receives an injury to the front of her brain, she may suffer more cognitive damage than a man injured in the same region fits nicely with these differences. Differences between the left and right hemispheres of the brain could explain why men tend to deal with problem solving by using the left half of the brain and taking a problem-solving approach akin to mathematics, while women typically solve problems using various grey-matter areas that are linked to language and are more aware of their feelings. There are also structural sex differences in areas of the human visual cortex which are related to the detection of motion. These might give males the better skills required for spatial targeting, and have possibly evolved from ancient hunting skills. Women, on the other hand, are better at detecting colour changes. It seems, as we have just seen, that personal choice rather than intrinsic ability underlies apparent sex differences in science-based careers. What about other skills, such as the performance of skilled motor tasks? One too often comes across beliefs in stereotypes, such as women are better at multitasking but are bad drivers and poor at parking. We will examine the evidence for these assertions.
In the United States a variety of skills are claimed by Diprete and Jennings to be important for success in primary school and girls have been found to have a considerable early lead over boys in these social and behavioural skills, which continues during their schooling. Moreover this female advantage persists when they go to college, and is considered to be the single most important factor underlying the significant lead that women have over men in rates of college completion.
There are a number of quite well established sex differences in skills related to cognitive functioning. Women are best at tasks involving verbal skills and episodic memory–recalling specific events–face recognition, perceptual speed and accuracy, and fine motor skills, while men typically have stronger spatial abilities, and are better able to process shapes and how the dynamics of these shapes change . . . We will return to verbal skills in the next chapter.
We have already mentioned mental rotation tests, where subjects have to compare three-dimensional objects or shapes in their heads. Men do very well with this test but most women struggle. Women have a thicker parietal region of the brain, which slows down their ability to mentally rotate objects. Research has shown that the sex difference in this ability is present in babies as young as five months, thus ruling out any idea that these abilities are determined by environment. Male hormones play a key role, and Berenbaum and his fellow researchers have demonstrated that women with CAH have greater spatial ability than their sisters throughout life. In addition women with a male twin usually have greater spatial ability than those with a female twin, as the male twin provides more testosterone in the womb. A well-established difference is that although men score higher than women on tests of spatial perception and orientation, women score higher than men on tests of memory for object locations, such as where a tin of soup is in a large supermarket. Explanations for such differences have focused on various causal factors, like biological evolution and the effects of prenatal and post-pubertal sex steroid hormones. Evolution has very likely played a key role. The paper by Lippa, Collaer and Peters suggests that some spatial abilities could have evolved from ancestral men’s devotion to tracking, hunting, targeting and projectile throwing which no doubt favoured the development of three-dimension visualisation skills and required the ability to visually track and target moving objects. By contrast, ancestral women’s focusing on foraging may have favoured the development of accurate memory for object locations and skill in locating foraging sites in relation to geographic landmarks.
Lippa’s paper quotes data from a BBC Internet study showed that, across fifty-three nations, men outperformed women on two visuospatial tasks. The extent of the male advantage tended to be positively associated with nations’ gender equality and economic development. As mentioned earlier, sex differences are usually larger in gender-egalitarian, economically advanced nations. Men are better not only at some visuospatial tasks, but also in auditory-spatial tasks. There are sex differences in extracting specific information of interest from a situation composed of multiple sound sources–the cocktail party as studied by Zündorf and his team at Tübingen University. Participants were asked to listen to sounds and determine the location of the sound source by pointing towards it or by naming the exact position. When sounds were presented one at a time, both men and women accomplished the task with great accuracy, but when several sounds were presented simultaneously and participants had to focus on and localise only one sound, women found the second task much more difficult than men.
Women do better on precision manual tasks involving fine motor co-ordination, such the assembly of circuit boards in a factory, and this may be a result of foraging skills that evolved a long time ago. This ability of women to perform better at fine motor activities may be due in part to their being more patient. Women also may do better on tactile tests, partly because they tend to have smaller hands.
While some studies have found that women with CAH resemble men by being better at mental rotation, other studies have found that male subjects with CAH show a paradoxically reduced skill for mental rotations. This is not understood. Most studies have found no differences in individuals with CAH for tasks such as verbal fluency or perceptual speed, at which women usually do better, though one study suggests they are less adept than other women at fine motor performance tasks. It is possible that exposure to testosterone in the womb has a greater impact on sexually linked motor abilities such as targeting in men and fine motor control in women. Girls and women with CAH are better at targeting–more like men. In women the menstrual cycle alters the performance of tasks related to motor and spatial ability, with high scores during the menstrual phase and low scores during the mid-luteal phase when higher levels of progesterone are found.
Experience can alter mental rotation skills. Children were given mental rotation tests before and after some training in how to do them and the initial gender differences disappeared following this training. More importantly, changes in the ability to do the rotation test can be brought about by information relating to which sex is best at it. Once again, stereotyping can affect performance. If women are told before a rotation test that men typically perform better, or that the task is linked with jobs such as aviation and engineering rather than jobs typically associated with women, they will perform worse. If they are told the opposite, women will do better. In another study those in the negative stereotype group showed greater activation of the amygdala, which is associated with fear and other negative emotions.
That differences in spatial reasoning may not be innate comes from a study in primitive societies. In one patrilineal primitive society, men outperformed women on a spatial reasoning task but that difference vanished when the test was given to matrilineal tribe members where women hold more power–then there was simply no significant difference between the sexes.
Another important spatial ability is differentiation of left and right. Confusion is common even in healthy adults. Women are more prone to such errors than men, as confirmed by tests asking subjects to identify the left or right hand in a drawing. Men are less likely to have to think about which way to turn a screw. They outperform women in overall spatial ability, but the sex differences in spatial memory are not the
same across all forms of spatial representation. Women have been found to excel at landmark memory images of differing types of structures. They also have an advantage in tasks related to declarative memory, the retrieval of long-term memories of specific events and facts, so may have an advantage in general knowledge. Hormones are once again involved and oestrogens may affect declarative memory, which is linked to the white-matter microstructure underlying the parahippocampus. Mendrek and her colleagues found an overall positive correlation between a normal range of circulating testosterone and successful visuospatial abilities in men, but men with both extremely low and extremely high levels of testosterone are associated with poor performance in this area–very puzzling.
Women have a very good episodic memory, a memory of autobiographical events in their lives including words or things that happened on a daily basis, while men are better than women at recalling non-verbal visual information such as remembering the way out of a wood. Men have been found to be better than women at finding their way when far from a goal. Women, on the other hand have been shown by Hassan and Rahman to perform better than men, on average, on tests of object-location memory. Specifically, women outperform men in location recall of objects that have exchanged places or shifted position, or when new objects are added to a previously studied array. They are thus better at remembering where they left the car keys.
In addition, as we have seen, women are better than men at remembering faces, especially of other women–perhaps because they give more attention to female than to male faces whereas men show no such own-gender bias. Women do better than men on all measures of facial recognition and these female advantages have been reported cross-culturally. Tests in which subjects must rapidly identify matching items are done better by women. Homosexual men are better at object-location memory than heterosexual men, and thus more like women, but on tests of spatial cognition they are less skilled than heterosexual men.
Tests on the ability to work out new spatial information from memory were based on experiments in which the subjects had to study line drawings of shapes linked either by straight or meandering lines, and then remember the straight-line distances. Men performed better. While women tend to rely on landmarks when they learn a route, either from a map or from direct experience, men are more likely to be aware of the compass direction in which they are travelling, and when using a map, the men made fewer mistakes in getting to a destination. So maybe the old argument that men are better at map-reading than women does have some validity.
There may be an evolution-based origin for the sex differences in spatial navigation as sex-related differences in this are seen also in other species. Hormones may again be playing a role, since if a female rat is injected at birth with testosterone, she learns how to get out of a maze faster. The right visual-association areas of the brain have been found to be more activated in men when doing spatial tasks in a three-dimensional virtual maze. Women, however, used additional regions on both sides of the brain for the more difficult spatial tasks. This difference was also found when doing mental rotation and numeric calculation (see Ira Epstein What Every Man Really Needs). Groups of young teenage boys and teenage girls attempting to find their way out of a maze again illustrate some of these sex differences. Whereas boys generally appoint a leader who has demonstrated his skills, and tend to search and explore the maze using scouts while remaining far apart from each other, girls tend to work in groups to explore the maze together without establishing a clear leader. So boys tend to use a command structure where girls use equal relationships and group co-operation in trying to discover how to find their way out.
Male superiority emerges on spatial tasks by the age of four, and this includes spatial tasks that measure accuracy. For example, large differences have been found with judgements about moving objects, such as studies that used ‘time to collision’ estimates. The tests are about the ability to judge when a moving object will arrive at a target, and the evidence is that males do much better at doing this. This may be related to sport, as testosterone levels from puberty are decisive with respect to physical performance by both male and female athletes in high-ranked sports. There is also a significant sex difference in throwing accuracy, which reflects the advantage of men in targeting abilities. There are also differences in spatial perception which requires targeting, such as hitting a target with a ball. Here again, men do better. Women are also worse than men at predicting the level of water when a half-filled bottle of water is tilted, but this may be due to a poorer understanding of basic physics.
Women have less upper-body strength than men, averaging only eighty per cent of that of men of identical weight. Sex differences in the ability to throw a ball far and accurately develop by the age of three. Men are also better at darts, but their steadiness makes women good at archery. There are currently no sports in which women are better than men, probably since men are bigger, stronger and faster and have better spatial and motor skills. But women are improving so rapidly that they may catch up even in competitions like the marathon, where the fastest woman is now just fifteen minutes behind the male champion. In the Olympics of 2156, women’s times may beat men’s in the hundred-metre sprint as the time difference between men’s and women’s speed has been getting less. There is also a possibility that stronger competition between women may lead to more practice and more intense play, which may in turn translate into superior skills and scores. Sex differences in motor abilities also have been related to testosterone exposure in the embryo and women with CAH showed more accuracy in throwing balls and darts at targets, and this finding was not related to an increase in the strength of their muscles.
The ability to conceptualise and manipulate tools in a complex manner is a distinguishing characteristic of humans, and was a major milestone in human evolution. Boys are more socialised with respect to technology as shown by three-year-old children during play sessions when they had to retrieve a toy which was out of reach using just one of six tools. The boys were more interested in objects and tried using the tools to get the toy. Using tools is a motor act and may involve mental rotation skills and boys and girls recruit different brain regions for tool use. Imitation can be important when learning new motor skills. Nichola Rice Cohen and her co-authors have shown that imitation is of critical importance in learning new skills. The imitation of hand movements involves a region of the brain in the left-hemisphere system known as the praxis system. In an experiment subjects viewed a sequence of hand gestures and then had to reproduce them from memory. The movement of the subjects’ hands were recorded by a special glove and analysed with a technique that identifies spatial and time differences between the original hand movements and the subsequent imitation. Results confirm a female advantage, as men left out more gestures from their remembered performance than women do. This difference reflects a female advantage when it comes to motor planning at the level of individual items. This female advantage is consistent with experiments with preschool children in which girls imitated gestures more correctly.
A recent official report by the United Kingdom Driving Standards Agency provides some evidence for the idea that women are not very good at parking a car, and are twice as likely as men to fail their driving test when trying to parallel park. Women needed an average of fifty-two hours of tuition to pass the test whereas men required, on average, just thirty-six. However, surveillance of British car parks has shown that while women may take longer to park, they are more likely to leave their vehicles correctly in the middle of a bay.
In relation to music and related motor skills, tests have revealed no significant differences between the sexes, but in a rhythmic ability test girls outperformed boys in four of the six movements. There may be some evidence that testosterone levels are related to talents in musical composition, as there are few famous women composers. In chess there has never been a female world champion, and only one per cent of Grand Masters are women. But the under-representation of women at the top end in chess
is what would be expected from the much greater number of men who participate in the game.
Men and women are thought to approach problems with different methods even if they have similar goals. They can solve many problems equally well, but their approach and the processes they use are often reported to be quite different. For most women, sharing and discussing a problem, as we have already seen, presents an opportunity for women to get to know better the person with whom they are collaborating. Women are also usually reported to be more concerned about how problems are solved than with merely solving the problem itself. They are said to think intuitively, and to be able to handle many sources of information at a time, but this can have the drawback of causing them to be overwhelmed by the complexities of a problem. They may also have difficulty in separating their personal experience from the problem in hand. Men, on the other hand, tend to focus on one problem at a time or on a limited number of problems, and apparently are more able to distance themselves from problems and minimise the complexity that may exist. But it is also claimed that in minimising difficulties they sometimes fail to appreciate subtleties that can be crucial for a successful solution.
When men, it is claimed, think about a problem or something that interests them, they keep their mind on it all the time and nothing else then exists for them except for what is related to that issue. On the other hand, women tend to do the opposite, and think more generally in trying to connect things up with other things. Do not try to talk to a man about something you feel is important while he is concentrating his attention on a specific problem or even on a football match, as it is unlikely you will get a useful response. As we have seen, men tend to process thinking better in the left hemisphere of the brain, while women tend to process equally well between the two hemispheres, and this may be why they approach problem-solving in different ways. Men rely more on the left brain to solve a problem one step at a time. Women make more use of the right hemisphere because they have more efficient access to both sides of the brain. This may help them to focus on more than one problem at one time, and they often prefer to solve problems using many simultaneous mental activities, which could help with multitasking. A lot of parents have observed how young girls can take part in a conversation among several other girls who may be discussing as many as three subjects at once. This leads me naturally to questions of language ability.
Why Can't a Man Be More Like a Woman? Page 12