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Here, women propose marriage and men can't refuse

Story Highlights
Woman presents special plate of fish to man; he takes a bite and is engaged
Matriarchal society exists in archipelago of 50 islands off Guinea-Bissau
Missionaries bring new concept of men proposing, causing strife in families
Women build the homes: Once completed, couple moves in, officially wed

CNN
4 Feb 2007

ORANGO ISLAND, Guinea-Bissau (AP) -- He was 14 when the girl entered his grass-covered hut and placed a plate in front of him containing an ancient recipe.

 Like all men on this African isle, Carvadju Jose Nananghe knew exactly what it meant. Refusing was not an option. His heart pounding, he lifted the steaming fish to his lips, agreeing in one bite to marry the girl. 

"I had no feelings for her," said Nananghe, now 65. "Then when I ate this meal, it was like lightning. I wanted only her."

 In this archipelago of 50 islands of pale blue water off the western rim of Africa, it's women, not men, who choose. They make their proposals public by offering their grooms-to-be a dish of distinctively prepared fish, marinated in red palm oil.

 It's the equivalent of a man bending on one knee and offering a woman a diamond ring, except that in one of the world's matriarchal cultures, it's women who do the asking, and once they have, men are powerless to say no.

 To have refused, explained the old man remembering the day half a century ago, would have dishonored his family -- and in any case, why would he want to choose his own wife? 

"Love comes first into the heart of the woman," explained Nananghe. "Once it's in the woman, only then can it jump into the man."

 'Now the world is upside down. Men are running after women'

But the treacherous tides and narrow channels that have long kept outsiders out of these remote islands are no longer holding back the modern world. Young men are increasingly leaving Orango, located 38 miles (60 kilometers) off the coast of Guinea-Bissau, a country in West Africa.

 They find jobs carrying luggage for tourist hotels on the archipelago's more developed islands; others collect oil from the island's abundant palm trees and sell it on the African mainland.

 They return bringing with them a new form of courtship, one which their elders find deeply unsettling. 

"Now the world is upside down," complained 90-year-old Cesar Okrane, his eyes obscured by a cloud of cataracts. "Men are running after women, instead of waiting for them to come to them."

 Standing in the shade of a grass roof, he holds himself upright with the help of a tall spear and explains that when he was young he took extra care to maintain his physique, learned to dance and practiced writing poetry -- all ways in which men can try to attract women, without overtly making the first move. 

'Now, with men choosing, divorce has become more common'

In recent years, young men have become increasingly bold, going so far as to openly propose marriage -- a dangerous turn, say traditionalists.

 "The choice of a woman is much more stable," explains Okrane. "Rarely were there divorces before. Now, with men choosing, divorce has become common."

 With records not readily available, it's unclear how many divorces there were earlier, but islanders agree that there are significantly more now than in the years when men waited patiently for a proposal on a plate.

 They waited some more, as their brides-to-be then set out for the eggshell-white beaches encircling the island, looking for the raw materials with which to build their new house.

 Women build homes; afterward it's official

Women built all the grass-covered huts here, dragging driftwood back from the ocean to use as poles, cutting blankets of blond grass to weave into roofs and shaping the pink mud underfoot into bricks. Only once the house is built, a process that takes at least four months, can the couple move in and their marriage be considered official.

 There are matrilineal cultures in numerous pockets of the world, including in other parts of Africa, as well as in China's Yunnan province and in northeastern Thailand, says anthropologist Christine Henry, a researcher at France's elite National Center for Scientific Research, or CNRS.

 But the unquestioned authority given to women in matters of the heart on this island is unique -- "I don't know of it happening anywhere else," says Henry, who has written a book on the customs of the archipelago.

 That things are changing is evident in the material chosen for the island's newest house: concrete. It was erected by paid laborers, not local women.

 Although priestesses still control the island's relationship with the spirit world, their clout is waning, as churches sown by missionaries have taken root.

 Missionaries bring upsetting new custom of men proposing

"When I get married it will be in a church, wearing a white dress and a veil," says 19-year-old Marisa de Pina, who strikes a modern pose under the blond grass of her family's hut, wearing tight Capri pants and sequined sandals. 

She says the Protestant church she attends has taught her that it is men, not women, who should make the first move, and so she plans to wait for a man to approach her. To make her point, the teenager pops into her hut and returns holding a worn copy of the New Testament, its pages stuffed with Post-it notes, letters and business cards.

 It's a decision that has caused strife inside the mud walls of her family's house.

 Like her niece, Edelia Noro wears store-bought clothes instead of the grass skirts still favored by some older women. She, too, attends church. But she says she doesn't see why these trappings of modern life should alter the system of courtship.

 More than two decades ago, she set off for the closest beach looking for the ingredients with which to propose to the man she loved.

 Noro waited for the tide to recede, then dug in the wet sand for clams, collecting them in a woven basket. She was embarrassed, she said, that she was too poor to afford a proper meal of fish and could only offer her groom-to-be what she could gather with her own hands. So after preparing the dish, she placed it in front of him, then ran and hid behind a tree, peeking out to see his reaction.

 "He did not hesitate and ate right away. I could see the love shining in his eyes," she said, a glow spreading across her cheeks.

 'I learned the hard way, a man never approaches a woman'

Although the island's unique customs may be fading, there are still pockets of resistance. Often, it's women who lure men back into the fold of ancient ways. 

Now 23, Laurindo Carvalho first spotted the girl when he was 13. He worked in a tourist hotel, wore jeans, and owned a cell phone and thought of himself as modern and so he thought he could turn tradition on its head, asking the girl to marry him. With the wave of a hand, she rejected him.

 Six years passed and one day, when both were 19, he heard a knock at his door. Outside, his love stood holding out a plate of freshly caught fish, a coy smile on her face. 

Carvalho still wears sandblasted jeans and flip-flops bearing the Adidas logo, but he now sees himself as embedded in the village's matriarchal fiber.

 "I learned the hard way that here, a man never approaches a woman," he says.

New Scientist
Dec 05

One's "chemical formula" depends on a number of factors, most notably whether we're talking about a he or a she. Male bodies contain more water than female bodies, which have extra lipids. By weight, oxygen amounts to about two-thirds of the body, followed by carbon at 20 per cent, hydrogen at 10 per cent and nitrogen at 3 per cent. Elements originating from pollutants would only be present in trace amounts.

If a human body were broken into single atoms, we would arrive at an empirical formula H15750  N310  O6500  C2250  Ca63  P48  K15  S15  Na10  Cl6  Mg3  Fe1. The relative numbers of atoms in this differ from the composition by weight because atoms have different masses.

BBC Online
16 Aug 2005
 
This is not down to conscious choice, but is related to survival of the fittest and a desire to pass healthy genes to offspring, say the authors.

When a woman is fertile near ovulation her partner preference shifts, the New Mexico University team found.

The study of 54 couples appears in the Royal Society journal Proceedings B.

Temptation

Researchers have already noted that women tend to be more attracted to men who have good symmetry, with the suggestion that this means they have "better" genes to pass on to offspring.

However, it is not always possible for a female to attract the most desirable male and some will settle for less but then seek out the genes they want by sleeping around, animal studies have found.

This so-called extra-pair copulation peaks around the time that the female is most fertile.

Dr Steven Gangestad and colleagues reasoned that a woman's interest around the time of ovulation would depend on the qualities of their partner - if the partner had good symmetry she would not be tempted to look elsewhere for a mate.

The team recruited 54 heterosexual couples to take part in their study.

All of the women were aged between 18 and 44 and were ovulating normally - none were taking the oral contraceptive pill.

The women were asked to report on their sexual attraction to and fantasies about both their partners and other men at different times of the month, including both fertile and non-fertile days.

'Trading upwards'

The researchers then compared the ratings with the symmetrical qualities of the partners' different body parts, such as ear length and width.

The women reported greater attraction to their own partners than to other men overall.

Attraction also peaked around ovulation time.

But at this time many of the women whose partners were asymmetrical tended to fantasise and become attracted to men other than their partner. Women with symmetrical partners generally did not.

Dr Nick Neave, a psychologist at Northumbria University, said the findings made sense and backed what was already known about human attraction.

"Females, like males, are always looking to enhance their reproductive success by trading upwards.

"They are always on the lookout for males with better genes or that have high social status/wealth as both enhance their reproductive success - offspring have better genes or access to better resources, both of which enhance their future reproductive success.

"Males simply go for women younger than their current partner as they are thus also able to enhance their reproductive success by producing healthier offspring."

March 15th, 2005
The following article by Diane Halpern was originally published in Skeptic, Vol. 2, No. 3, pp. 96103, which was based on a lecture delivered by Dr. Halpern at the Skeptics Society Science Lecture Series at Caltech, Sunday, April 18, 1993. We present it here in response to the brouhaha surrounding the comments by Harvard University President Lawrence H. Summers, who told Harvard faculty members that the likeliest explanation for the gender differences in math and engineering is inherent differences in cognitive abilities, not upbringing, education, or career choices. As always at Skeptic, we prefer to set politics aside and follow the science.

Dr. Diane Halpern is an international authority on the scientific study of gender differences, cognitive abilities, critical thinking, and family dynamics. She is the author of Sex Differences in Cognitive Abilities, Enhancing Thinking Skills in the Sciences and Mathematics, Thought and Knowledge: An Introduction to Critical Thinking, and Changing College Classrooms. She is Professor of Psychology at Claremont McKenna College and was the 2004 President of the American Psychological Association.

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When it comes to gender differences in cognitive abilities anyone who maintains a reasonable amount of skepticism may already be viewing this subject with the same open mindedness that you would apply to recent Elvis sightings. So much has been said and written on sex differences in cognitive abilities that it is difficult to separate the various claims and come up with empirically supported conclusions. My plan is to present some of the theories and research that have explored individual differences in cognition, and discuss what we know and what we do not know.

I am a cognitive psychologist and it is my interest in how we think that is the thread tying these seemingly diverse topics of sex, brains, and hands together. Like any detective, I have followed some intriguing clues about individual differences in human cognition and have reached some controversial conclusions. For the last several years I have been involved in what I have called trial by media or science by press release. One of the problems in discussing sex differences in thinking is that the public has received so much misinformation from the press, who are more interested in grabbing the readers attention and meeting a deadline than in understanding complex issues. Reporters tend to prefer misleading headlines that have more to do with selling newspapers than with the actual content of the articles. This is not good for science. It is not an unbiased process, and I have begun speaking out against it, especially when I found myself being misquoted and quoted out of context.

When I went into cognitive psychology I did not plan to conduct controversial research. It started when I was teaching courses in cognitive psychology and the psychology of women, and the same question about the relationship between sex (or if you prefer, gender) and cognitive abilities came up in both classes. It seems that almost everyone is interested in this topic, which is probably why it has received so much press coverage in the last several years.

In order to answer the question of how women and men differ in their thinking, I began to review and synthesize the research literature on sex differences in cognitive abilities. If you ever try a computerized search in this body of literature you will be overwhelmed with the number of citations on these topics. About 14 years ago when I was conducting my research for the first edition my book Sex Differences in Cognitive Abilities, I had planned to show the weakness of the evidence in support of biological bases for any claimed cognitive differences between the sexes. If there were any differences, it seemed to me that they must be small and insignificant. Instead I found that the differences are sometimes large and that some of the biological data used to explain the differences were too strong and too consistent to ignore. I also found that the effects are not simple, and that other variables influence the findings. We usually talk about laterality as left or right handedness, but it is really a continuous variable that extends over many different indices of right or left sidedness. Laterality interacts with sex so that the kind of answers we get to questions about sex differences in cognitive abilities depends upon what I call sex bilaterality interactions. That is, some of the results seem to depend on both ones sex and ones preferred hand.

In discussing gender differences in cognitive abilities, I sometimes feel like a dentist who unexpectedly hits a nerve while drilling in the mouth of a sleeping giant. The reason for the intense nature of this controversy is easy to understand. There are serious social and political ramifications to concluding empirically that there are systematic sex and laterality differences in cognitive abilities. Such conclusions have a tremendous potential for misuse and abuse. They could be and have been used, for example, to justify discrimination, and or affirmative action based on ones sex and preferred hand. Since sex and handedness are biologically determined variables that are not subject to individual control, then one is stuck with what one has. If these variables are also linked to thinking skills, then it implies that some aspects of intelligence and cognition are biologically determined. From there it is a small step to concluding that if some groups (e.g., gender or preferred hand use) think differently, there is nothing society (the environment) can do about it. As we know, this sort of information has been misused to discriminate against groups of people in the past. So I certainly do understand the controversies involved. But that does not mean we should not study the issues.

The study of sex differences has also been criticized as being inherently sexist, because it creates an emphasis on the way women and men differ, while ignoring the multitude of similarities. This is undoubtedly true. But I find the reasons for conducting such research to be much more persuasive than those against doing so. First, arguments against studying individual differences are frequently based on the assumption that if the truth were known, womens deficiencies would be revealed. In my text, Sex Differences in Cognitive Abilities, I call this the women have less fallacy. This is simply not true because researchers have shown that there are areas in which females, on the average, excel, and areas in which males, on the average, excel. But differences are not deficiencies. The study of sex differences, like any of the other individual or group differences that psychologists study, is not a zero-sum game where one group gains only at the expense of another. The problem lies not in the fact that people are different. It is in the value that we attach to these differences. Second, it is only through such studies that similarities can be revealed. We cannot understand the ways in which people are similar without also examining the ways in which they differ. You simply cannot study similarities without studying differences. Perhaps most importantly, sex differences research is the only way that we can empirically determine if common myths and stereotypes about men and women have any basis in fact. The sole alternative to knowledge is ignorance, and ignorance does not counter stereotypes or dispel myths. High quality research is the only way we can determine whether, when, and how much women and men differ. It is the only way that we can reject false stereotypes and understand legitimate differences.

The question of gender differences is really a set of questions and not a single question. I have organized the issue around five questions:

Are there sex differences in cognitive abilities? In other words, is there sufficient solid empirical evidence that females and males, on the average, perform differently on valid tests of cognitive abilities? The other questions are only meaningful if we conclude that, in fact, some differences exist.
If there are differences, when in the life span do these differences appear? Are they present at very young ages or only later in life?
How large are the differences? In other words, even if there are statistically significant differences, are they large enough to be of any practical importance?
Are the differences due to factors inherent in the biology of maleness and femaleness, or are they due to cultural and environmental experiences and expectations? Theoretically, this is the most important question and one that is familiar to all students of psychology. There are mountains of literature on this subject. When I put the books and journal articles together that I have used for the background to my research, I can measure them in yards. Despite all this research, we are still wrestling with that age old question of whether nature or nurture plays a greater part in sex-related cognitive differences. These are exceptionally controversial and extremely political questions. And like all loaded questions the answers we get sometimes backfire. Results can and have been used in ways that support discrimination, and programs used to redress discrimination. Science in this area is not impartial.
The final question is an applied one, and for many reasons may be the most important one. As concerned citizens, parents, researchers, educators, and especially scientists, math educators, and skeptics, what should we be doing with this knowledge?
I am going to start my discussion with the first question. Are there valid sex differences in cognitive abilities? I have told my students that all difficult questions in life have exactly the same answer: It Depends! The answer to this first question depends on whether, where, and when we find sex differences in cognition, and what variables cause these differences. First, it depends upon the specific cognitive ability that we are examining. The majority of the literature in this area has investigated differences in three different cognitive domains: verbal, visual-spatial, and quantitative abilities. But terms like verbal, visual-spatial, and quantitative are category headings used to organize and study cognition. They are not unitary constructs. Verbal ability for example, applies to all the components of language usage, including skills like word fluency, grammar, spelling, reading, vocabulary, verbal analogies, and language comprehension. Examples of items used to tap verbal ability include selecting words that most nearly are the same in meaning; a variety of vocabulary type questions; verbal analogies (e.g., an igloo is to Indian, as tepee is to: ice, canvas, eskimo, or home); reading comprehension, where you would have a complex passage and are asked questions about the material that has been read; simple grammar questions (e.g., which is correct: give the money to Bob and me, or give the money to Bob and I?). You can see that these are certainly not tapping the same sort of skills even though they all involve language.

Spatial abilities are also not unitary, and there are a least four separatable components to spatial abilities. One of these components involves spatial perception. If you were a subject in an experiment looking at some of these differences, you might be given what is called the rod and frame test. (It is an old test that has been around many decades and has a terrible history of being misused in psychology). If you were a subject in this experiment, you would be sitting in a darkened laboratory with a tilted frame that is glowing in the dark. You would have a knob in front of you, and by turning the knob you would adjust the position of the rod within the frame to the vertical. What we find is that some people are good at aligning it to the vertical, while others are influenced by the tilt of the frame. That is a test of spatial perception.

Quantitative ability is also a heterogenous field. Consider the differences among tasks like simple rote multiplication, word problems, and other more advanced topics in mathematics, some of which are spatial in nature, like calculus, topology, and geometry. Whether and when you find sex differences depends upon the ability being assessed. Differences among the type of test given, the nature of the subject pool, and numerous other factors have generated numerous contradictory findings and unreplicated claims (and some name calling for good measure). The short answer to what is really a long question is yes, there are some tests of verbal, visual-spatial, and quantitative abilities that show consistent sex differences. But the short answer does not do justice to the literature because there are so many tests that do not show such differences.

Sex differences are most reliably found in the tail ends of mental ability distribution (by this I mean a bell-shaped curve which is normally distributed with the upper and lower ends as the tails). Consider the highly publicized studies by Benbow and her colleagues concerning mathematically precocious youth who score extremely high on the mathematics portion of the SAT test. As most of you probably know, and I am going to assume you know this because it has been carried in every major newspaper, news magazine, radio, and television show, males substantially outnumber females among this elite group of young people. The statistics are startling: sex differences in the ratios of males to females are two to one for those scoring over 500, four to one for those scoring over 600, and 13 to one for those scoring over 700! This does not mean, of course, that there are no girls in this group or that girls cannot attain the highest levels of math achievement. Obviously the girls are there, but they are there in reduced numbers relative to the number of boys.
 

Similarly, dyslexia, a severe reading disability found in individuals whose other cognitive abilities are within normal ranges, is also predominantly, though not exclusively, a male problem. Approximately two percent of the school population is dyslexic. (It might interest you to know how they get this figure. There is funding for two percent of the school age population, so two percent are dyslexic. If a kid changes school districts he or she could become dyslexic or nondyslexic depending where the cut is made. Moderate dyslexia is five times more likely to occur in males than in females, and severe dyslexia is ten times more likely to appear in males. Dyslexia is also more likely for left-handers than for right-handers. These data demonstrate strong sex-related differences, but we need to keep in mind that differences are much smaller for the vast majority of the population that does not fall into the tails of the distribution. So for most of the population, the differences are much smaller in size.

When in the life span do these differences appear? You can probably guess the answer to this question: It depends! It depends upon the type of test that is given and who is being tested. Some of the differences show up very early in life. There are reports that girls, on the average, talk sooner than boys. They have what we call longer mean utterance lengths a psychological term describing how children string words together in the language acquisition process in order to communicate. Girls develop the use of passive voice and other complex grammatical constructions and advanced comprehension at an earlier age than boys. We are talking about the quality, not the quantity of what is being learned and produced. It is interesting to note that there is one traditional verbal area in which males excel, at least at adolescence, and that is in solving verbal analogies.

Consider, for example, the figure below which displays the time trend in sex differences on the verbal portion of the SAT test.
 

Developmental trends in quantitative abilities are harder to pin down. There seems to be a clear advantage in arithmetic for girls in the early elementary school years, with several tests showing girls out-scoring boys in computational arithmetic. All of those tests that children take nationally and internationally, in the early grade school years show that girls, on the average, score higher than boys. But, the trend reverses in early to mid-adolescence, when the advanced math courses are introduced. This finding is complicated by the fact that there are a number of other changes that are occurring at early to mid-adolescence, any one of which could help explain the data. As to the trend of the mathematical portion of the SAT, it is dramatically flat, if one can have a dramatic non-trend. What we see here from 1967 on for a 25-year period, males are scoring 47 to 50 points higher than females on the average across all those years.

The literature on aging shows that verbal abilities in general tend to stay high into old age. Spatial skills seem to decline at a more rapid rate for everyone as we age. The aging literature, of course, has to be interpreted with extreme caution because of the obvious problems in cross generational comparisons. Sex differences for cognitive abilities in the elderly are extremely difficult to study. For starters, it is very difficult to get large samples of old people, particularly older men. As you probably know, men on the average die six to seven years younger than women.

At least some of the cognitive differences are quite large, although most of the differences are not. The effect size for tasks involving rapid mental rotation, for example, is among the largest effect sizes in the psychological literature. It is almost one standard deviation. This means the two sex distributions are almost one standard deviation apart. That is a lot. Conceptually, this effect size is as large as the difference in IQ between college freshmen and their professors. (When I tell this to college freshmen they are, amusingly, unimpressed!) Or alternatively, this is as large as the difference in height between 13-year old and 18-year old girls.

Although there is less research on handedness with these tasks, it seems that left handers also excel at mental rotation tasks. There are also reports of very large effects on spatial-temporal tasks favoring males, and tests of associational fluency favoring females. The effect size for something like associational fluency (finding words with similar meaning) is almost one and a quarter standard deviation units apart. Cohen, who is the guru of effect-size statistics, has interpreted effect size of this magnitude as so large that tests of statistical significance are not needed. The data are self-evident. They need nothing more sophisticated than a binocular test of significance. (If you are not familiar with this high level statistical jargon, a binocular test of statistical significance consist of looking at the data with both eyes open and concluding that they are different.) There is little overlap in the distributions. These effects are much larger than those found in psychological research in other areas and fields of study.

The largest differences are found on timed tests, particularly reaction time tests, which are frequently the dependent measures in mental rotation studies. Although the effect sizes are large compared to the other topics psychologists study, when the dependent measure is reaction time, we are dealing with differences that are measured in fractions of a second. We measure reaction time typically in milliseconds, so the unit is a thousandths of a second. Practically speaking I do not know what it means to say there is a 40 millisecond, or a 200 millisecond, even a 500 millisecond difference, or whether these differences in fractions of a second add up to some practical significance at the end of the day. That is not the kind of question for which I think we have answers. Even when you have these larger effect sizes their practical significance is unknown.

The division of abilities into verbal, visual-spatial, and quantitative has been useful, but there are alternative ways of investigating the thinking process. One way is to think about what it is an individual does when she or he is engaged in a particular task. I may be more useful in understanding the data to look at the underlying cognitive processes. I have summarized some of the tasks in which males and females tend to differ. In general, those tasks in which females tend to excel and exhibit large differences involve generating synonyms, producing language fluently, and computing and solving anagrams. The underlying cognitive process for these tasks seems to involve rapid access to and retrieval of information in memory. By contrast, the tasks in which the literature shows that males excel are verbal analogies the mapping of meaning in relationships, mathematical problem solving, mental rotation and spatial perception, and using dynamic visual displays. Here the underlying cognitive processes involve manipulating and maintaining a mental representation. There is a large body of literature in cognitive psychology related to the issue of sex differences that looks at those processes involved when individuals use their short term visual memory to access information from long-term memory, so this conceptualization fits with the mainstream cognitive literature. Theoretically the most interesting question to ask is why do these differences exist? I am certain that the differences are due in large part to socio-cultural factors. If you look at cross-country data, and within countries analyzing for socio-economic status, virtually every investigation shows large main effects for culture. Undoubtedly much of the difference is due to variables like culturally determined sex roles, expectations, and learning histories, which include the kinds of toys we are given as children and the adult roles to which we aspire. Thus, data must always be interpreted in the context of the society in which they are collected.

Although I believe that we cannot underestimate the importance of environmental variables, what I would like to do for the rest of this presentation is summarize some of the evidence of the biological explanations for at least some portion of the sex differences found with cognitive tests. The socio-cultural influences are relatively noncontroversial in that virtually every researcher acknowledges that they are important. In addition, numerous biological explanations have been proposed. In considering these biological hypotheses, however, I keep hearing a little voice something I read when I was an undergraduate by a psychologist named Weinsteen who offered this sternly worded caveat biology has always been used as a curse against women. I try to keep her warning in mind whenever I review biological theories of cognitive sex differences.

Some have suggested that psychology should not study the biological basis of sex differences because biologically-based theories legitimize negative stereotypes of women. I respond to these critics by noting that silence does not counter stereotypes, ignorance does not promote equality, and differences are not deficiencies. We have had stereotypes a lot longer than we have had research. I think it is time to look at what research has to say. I understand, however, the concerns of those who fear biologically-based theories. Some of the theories have been ludicrous, for example, the hypothesis that women have smaller and therefore inferior brains, an idea very popular around the turn of the century or the mistaken notion that women should eschew serious academic pursuits because studying these topics would use blood that was needed for menstruation.

One hypothesis that has garnered recent support concerns sex differences in lateralization and/or structures mediated by prenatal hormones, prenatal stress, and or sex differences in adolescence maturation rate. Let me provide a very brief introduction to this very complex area. A large body of research has revealed that for most right-handed people, the right hemisphere tends to be more dominant for nonlinguistic spatial tasks, and the left hemisphere more specialized for verbal tasks. About half of all left-handers show this pattern of dominance, with the remainder showing either reverse dominance or equal representation of these tasks in both hemispheres. Thus, hand preference became a rough and imperfect indicator of brain organization. (You may be interested to know that critics of the original studies criticized this work because the researchers used Caltech students for subjects. The critics said Caltech students were atypical and results obtained with such unusual subjects could not be generalizable back to the general population.) Hand preference research parallels sex difference research in many ways, some of which I have already mentioned. Left-handers are over-represented in certain categories of mental retardation, are more likely to be dyslexic, and more likely to have stuttering problems. They are also more likely to be among talented adolescents identified as mathematically precocious, and they are over-representated, relative to their proportion in the general population, in architecture and mathematics. So what we have again is differences, not who or which group is better. Given that the type of abilities that differ by hemisphere of representation are the same ones that differ by sex, it seemed to be only a short leap to then argue that the sexes differ in the way their hemispheres specialize these abilities. There is a large body of experimental research using such paradigms as dichotic listening, direction of eye movement during cognitive tests, post mortems, EEGs, split brains, WADA Test, patients following localized brain surgery, and speeded tapping and hand movement. The results that came from these diverse paradigms are not entirely consistent, and I think it would be surprising if they were because they are so different in terms of what they are looking at. However, when differences are found, they usually support the notion that females maintain a more bilateral organization of cerebral function, at least for verbal tasks, and males more often demonstrate greater cerebral lateralization. Other researchers have demonstrated differences in the way cognitive structures are distributed by function within each hemisphere. Another sex-related brain difference that may be important in cognition (and has been replicated several times) is the finding that there is a portion of the corpus collosum a thick band of neural fibers that connect the two halves of the brain that is larger in females than in males and larger in left-handers than in right-handers. The most recent research in this area is showing that prenatal ovarian hormones are important determinants in the size of the corpus collosum. Although it is a long leap to extrapolate from brain structure to ability and behavior, numerous researchers have suggested exactly this sort of link.

The idea that the brain is a sex-typed organ has generated a great deal of interest. There is a large and growing body of literature that suggests that cognitive abilities vary both as a function of ones sex and preferred hand, that is, whether you are more or less left or right sided. Some of the most recent research is showing that prenatal hormones, the ones that direct and reflect the sexual differentiation of the fetus, are the same ones that determine handedness. Consider, for example, a large study in which the researchers reported sex by handedness interaction on cognitive tests. They used three large samples in different geographical areas of the country, so they had built-in two replication samples. They used multiple measures of spatial and verbal ability, and they found that while, overall, males performed better than females on 14 out of 15 of the different spatial tasks, across three geographically distinct samples, they found that left-handed males performed poorer than right-handed males on all 15 of these tests across all three samples. On the other hand, left-handed females performed better than right-handed females on 12 of these tests. Reverse results were found with verbal abilities with right-handed females out performing left-handed females, and left-handed males out performing right-handed males. It is not important that you keep the specific sex by handedness interactions straight; what is important is with replications and large numbers of tests, many psychologists are finding differences that depend on ones sex and ones laterality. Sex by handedness interactions have been noted by numerous other investigators, although they are not all easy to interpret.

These results are particularly important because we have no reason to believe that sex role pressures, learning environments, or any other psychosocial variable differs as a function of laterality. That is, there is no environmental hypothesis that we have that can explain these results. We do not socialize left-handed girls differently from right-handed girls, or left-handed boys differently from right-handed boys.

There are several theories that have been designed to explain some of these sex by laterality differences. The most popular one is by Geschwind and Galaburda, who proposed a biological theory of cognitive sex differences. They believe that prenatal hormones are important determinants of brain development. By itself, that is not a very controversial position. Geschwind and Galaburda also found strong positive relationships among left-handedness, high levels of prenatal testosterone, both chemically induced (people taking drugs) and secondary to maternal stress, and allergies such as asthma, hay fever, and other immune disorders, particularly those involving the thyroid. We also know that there is a greater proportion of males than females who are left-handed, which would be predicted by this theory, because males are exposed to greater levels of prenatal testosterone. The next plausible question is whether there are any data that might support this relationship among sex, handedness, prenatal hormones, and cognition. The answer is yes.

As I already mentioned, Benbow and her colleagues found large and consistent sex differences favoring males among those who are most gifted in mathematics. This difference is found in early adolescence prior to differential course taking, and prior to, in most cases, the onset of adolescence. Using the same subject pool, Benbow has recently documented physiological correlates of extreme mathematical giftedness that includes significant increase in left-handedness, allergies, myopia, and relatively late puberty, on the average. The underlying theoretical position is that the same prenatal hormone that determines the sex of the developing fetus also influences other organs that are being formed at the same time, notably the left hemisphere. According to Geschwind and Galaburda, the left hemisphere matures at a slower rate than the right, therefore is more vulnerable to a whole variety of influences. The theory proposed by Geschwind and Galaburda, and others, is that high levels of prenatal testosterone cause slow neuronal growth in the left hemisphere and impair development of important immune system structures (the thymus). With this model, they predicted and found positive associations among being male, left-handed, immune disorders, and anomalous right-hemisphere abilities.

It is very difficult to explain associations among a set of variables as diverse as these without some sort of unifying theory that would help to tie them to some common origin or common influence. Unfortunately this gets even more complicated. Other evidence in support of Geschwind and Galaburdas hypothesis were provided by Sanders and Ross-Field. I believe they were among the first researchers who reasoned that male homosexuality might also be determined by the same prenatal variables that are involved in cognitive sex differences. This possibility lead to the prediction that male homosexuals, as a group, would resemble females in their cognitive abilities more than they would resemble heterosexual males. Using several different tests of spatial ability, they found that their samples of male homosexuals demonstrated spatial abilities similar to that of the female samples. Both male homosexuals and females were significantly lower in their visual spatial abilities than the heterosexual males. They replicated this finding in three different experiments, and it has now been replicated by several other investigators. It seems that many people are supporting the same finding. There are also several reports in the literature showing that male homosexuals and male and female transexuals, are more likely to be left-handed than any other groups. This suggests again that these variables are related in ways that are not easy to unravel.

We certainly do not have a tight package of explanations, but we have, perhaps, some hint at what is happening. Additional support for the notion that sex hormones affect cognitive processes come from the highly publicized studies (front page news, above-the-fold kind of studies), that say there are slight variations in cognitive performance for menstruating women, as a function of the portion of the menstrual cycle they are experiencing. Recent studies of girls with Congenital Adrenal Hyperplasia (CAH), a condition in which girls are exposed to high levels of adrenal androgens prenatally also support this relationship. CAH is usually detected soon after birth and corrected. So we have a group of girls who differ from normal girls only in that they were exposed to high levels of androgens prior to birth. Relative to control groups, the CAH girls score extremely high on tests of visual-spatial ability. They also show strong preferences for what experimenters identify as boy-typical toys (transportation and construction toys). Other researchers found that males with extremely low levels of testosterone in adolescence have extremely poor visual-spatial abilities. These results, along with other experimental findings, support the crucial influence of sex hormones on cognitive abilities. These data are consistent with a huge nonhuman animal research literature that shows the gonadal hormones play a major role in the development of sex differences in behavior in the brain in a variety of other species. They are not readily amenable to psychosocial explanations. They are also not popular data. I am more comfortable making fun of studies, like the one that show prenatal hormones affect the toy preferences of toddlers, than I am with seriously trying to explain them. I grew up in the decade of the 1960s and at that time, I had very clear notions about the determinants of sex differences. I was especially interested in what caused human behavior which is why I became a psychologist. I argued my beliefs with fervor and I have never been surer about anything as I was in the 1960s. I recited what I call the old party line. First, there are no sex differences, other than those involved in reproduction. I remember arguing with one of biologist, telling her that I wanted to know about the important differences. She looked at me and said, reproduction is important. So I realized then that I would have to clarify my interests. I believed that any evidence showing cognitive sex differences could be explained by experimenter bias, by flaws in the data, sloppy researchers, etc. In the 1960s I believed that I could explain away any study that found differences. But as the data was accumulated and the evidence that there are sex differences in cognition became impossible to ignore, I changed my explanation of choice and I espoused the point of view that the differences were too small of be of any practical significance. I really perfected my small-effects size argument. It seemed that just as I perfected that argument, large-effect sizes began creeping into the literature. When this response would no longer work, I once again knew with certainty that such large differences that were found could be attributed completely to differential socialization practices. In this way I was able to maintain for many years a tidy explanation of how and why females and males differ with regard to variables that are unrelated to reproduction.

What do I know now? Well, I know a lot more, but am certain about a lot less. I discovered that explanations of cognitive sex differences are much more complex than some single point along a continuum with biological at one end and psychosocial at the other. We will never be able to say, for example, it is 40% of one and 60% of the other. I now know that psycho-bio-social interactions are needed; ones that, in fact, recognize the reciprocal effects that psychology, biology, and sociology have on each other. I know that we need a theory that recognizes that experience alters the biological underpinnings of behavior. Our experience changes our biology, which in turn, influences the types of experiences to with we are exposed. Our knowledge of the way brain structures and organization direct cognition is still sketchy and incomplete. It is probable, if not absolutely certain, that current theories will be replaced with more sophisticated ones as our knowledge about the relationship between brain structure and organization and cognitive abilities increase. None of this is meant to imply a new breed of biological determinism. Biological theories do not imply inevitable or immutable outcomes. We also have to learn from our past theories that seemed promising at first have not held up under repeated investigation. The same fate may befall todays theories of differences in brain structure and organization.

For our colleagues who are in the business of education, I want to stress that all of the evidence supports the notion that most cognitive skills are readily educable or trainable. Despite the intriguing nature of the recent biological hypothesis, it is important to keep in mind that the single most important determinant of whether girls take higher level mathematics or not is parental attitude, not ability. The most important determinant of achievement in any field is educational level. As a society we should be concerned with developing the intellectual potential of every individual to its fullest.

The reason for this concern is not merely altruistic. In an article in Science, Stein reported that mathematical achievement among the top 5% of 12th graders is lower in the United States than any other industrialized nation. Eighth graders in the United States are below international norms in solving problems that require higher order thinking skills. In the United States more than two-thirds of all the bachelors degrees and 80% of the doctorates in mathematics are earned by Asian and white males. If biological variables are involved in determining quantitative or mathematical ability, or any other ability for that matter, their effects are much too small to account for this order of magnitude. Biological theories also cannot explain the scarcity of males from other minority ethnic groups in higher mathematics and in the sciences. The biology of femaleness and maleness does not change as a function of ethnicity. Even the most able girls begin dropping out of advanced mathematics as soon as these courses become optional. By the 7th or 8th grade we are losing our very best. It is important to encourage all able students, but particularly girls to stick with math. As citizens and as educators we have an obligation to help girls and boys realize that math counts. It is also important to provide visual-spatial training as early as possible in the elementary school years. The importance of visual-spatial skills has been recently been shown by Casey, for scores on test of visual-spatial ability can predict whether girls will select math or science majors in college. We have remedial reading classes filled mostly with boys, but almost no curriculum to encourage the development of visual-spatial skills that the data suggest would be needed more often by girls.

Finally, we must not fall prey to the dangers of self-fulfilling prophecies. The data presented here represents average differences, based on large samples of males and females. No single individual is average. Group average data have little to do with individual performance. There is considerable between-sex overlap in all of the cognitive abilities, with large numbers of males demonstrating high verbal abilities, and large number of females demonstrating high visual-spatial quantitative abilities. The literature concerning cognitive sex differences has been proliferating in recent years because the questions are of profound human interest. But the most important issue is not how women and men differ on the average. We should keep in mind the words of the 18th-century British writer who was once asked, Which is smarter, men or women? He replied: Which man, which woman?
 

Bad driving 'linked to hormones'

Map reading and parking may prove difficult for some women because they were exposed to too little testosterone in the womb, researchers suggest.

BBC
24 January, 2005

The study, in the journal Intelligence, fuels the age-old male myth that women are deficient in these skills.

Scientists from the University of Giessen, Germany, found a lack of the hormone affects spatial ability.

Low testosterone levels are also linked to shorter wedding ring fingers, they say.

The research looked at the spatial, numerical and verbal skills of 40 student volunteers.

Men do seem to be better at spatial abilities, and women at verbal and emotional skills
- Dr Nick Neave, British Psychological Society

Spatial skill is the ability to assess and orientate shapes and spaces. Map reading and parking are spatial skills which men often say women lack. Women tend to disagree.

The researchers also looked at the length of the students' wedding and index fingers.

In women, the two fingers are usually almost equal in length, as measured from the crease nearest the palm to the fingertip. In men, the ring finger tends to be much longer than the index.

For one of the spatial tests, volunteers had to tell which of five drawings could not be rotated so it looked like the other four.

The other test involved the ability to think in 3D by mentally "unfolding" a complex shape.

Overall, men achieved higher scores in the tests than women.

But women with the male pattern of finger length did better than those whose wedding finger was shorter.

They also scored better on the numerical tests.

Fertility

Writing in Intelligence, the researchers, led by Dr Petra Kempel, said women who had 'male-like' finger length ratio patterns outperformed other women.

They added that the differences seen within the group studied were "remarkable."

However, the researchers accept that their study was limited because only one saliva sample was taken from each person, and no detailed account was taken of women's menstrual cycle, which can affect hormone balance.

Other studies looking at finger length ratio have suggested that, in men a long ring finger and symmetrical hands are an indication of fertility, and that women are more likely to be fertile if they have a longer index finger.

Another study controversially suggested that finger length ratio could also be linked to sexual orientation, with lesbian women having a greater difference in length between their ring finger and index finger than straight women do.

Dr Nick Neave, an evolutionary psychologist at the University of Northumbria who specialises in spatial awareness and gender differences.

He said: "Being exposed to testosterone early on does seem to affect the way the brain works.

"It seems to push it to work in a more masculine way, with a stronger right hemisphere; the spatial hemisphere.

"The extra testosterone also appears to cause the ring finger to be longer than the index."

Bones contain testosterone receptors, and Dr Neave said the fourth finger appeared to be particularly receptive to levels of the hormone.

Higher levels are linked the ring finger being longer than the index.

Dr Neave, a member of the British Psychological Society, added: "The sexes do use different skills to find their way around. Men seem to be able to keep the route in their head without landmarks, whereas women do use them.

"So men may be better at finding the car when its parked in a huge shopping centre car-park. It may also tap into driving and parking abilities."

He added: "Men do seem to be better at spatial abilities, and women at verbal and emotional skills.

"It may be a generalisation, but that does seem to be the case."

Love's strange effect on people
Love really does have a strange effect on people, say scientists.

2004/05/05

Italian researchers carried out tests on 12 men and 12 women who had fallen in love during the previous six months.

They found that men had lower levels of testosterone than normal, while the women had higher levels of the hormone than usual.

"Men, in some way, had become more like women, and women had become like men," Donatella Marazziti of the University of Pisa told New Scientist
magazine.

"It's as if nature wants to eliminate what can be different in men and women, because it's more important to survive at this stage," she said.

'Love is blind'

The findings come as another study suggests that love may indeed be blind.

Researchers at University College London have discovered that being in love can affect key circuitry in the brain.

They found that the neural circuits that are normally associated with critical social assessment of other people are suppressed when people are in love. They said the findings may explain why some people are often "blind" to their partner's faults.

Both studies add to the growing evidence that love can have a strange effect on the body.

Previous research by the Italian researchers, published in 1999, suggested falling in love played havoc with key chemicals in the brain.

They found that people who were in love had lower levels of serotonin.

In fact, their serotonin levels were found to be the same as people with obsessive compulsive disorder.

Speaking at the time, the researchers said the finding may explain why people who are in love can sometimes obsess about their partner.

Love drugs?

Professor Gareth Leng of the University of Edinburgh is also carrying out research in this area.

"It's about understanding ourselves a little bit better," he told BBC News Online.

But Professor Leng said the research could one day lead to new treatments for people who are having relationship problems.

"We know that a very large proportion of adults do report dissatisfaction with bonding or sexual experience.

"I wouldn't rule out the possibility of some sort of therapeutics in the future," he said.

BBC MMIV

 

Chimp youngsters a lot like humans
Females learn much faster while males romp around

By Marsha Walton
CNN
April 2004

Now there is scientific evidence suggesting our evolutionary cousins, chimpanzees, exhibit gender-specific learning experiences.

A study of a primate behavior called "termite fishing" by a community of chimpanzees in Tanzania found that young females picked up the food-gathering technique much faster than males. Both sexes ultimately mastered the skill by the time they reached 5-and-a-half years old.

"Female chimps that we studied tended to learn the skill about 27 months earlier than male chimps," said Elizabeth Lonsdorf, a primate expert at Chicago's Lincoln Park Zoo. "Little girl chimps at the termite mound, even at very young ages, tended to watch their mothers more and pay close attention, while little boy chimps were off kind of playing around in the trees and doing somersaults," she said.

Chimps fish for termites by selecting a stick to probe the tunnel of a termite mound. The clever primates then pull out the stick for a tasty, high protein snack. That technique has been observed continuously in Tanzania's Gombe National Park since Jane Goodall first began her work there in 1960.

"Termites are a small part of their diet, but a highly valued part," said Lonsdorf. "Termites are sort of like 'chimp bon-bons,' they go crazy for them."

Lonsdorf and her colleagues spent four years studying termite fishing at the chimp community in Tanzania. The study involved animals as young as 3 months and as old as 11 years. The researchers ruled out that different treatment from their mothers affected how the youngsters learned.

"We found that mothers showed no differential behavior toward their sons versus their daughters. They weren't being nasty to their sons or encouraging to their daughters," said Lonsdorf.

The differences in learning may have an impact on what they do later as adults.

The boy chimps, who spend more time climbing, playing and roughhousing as youngsters, do more hunting than females as adults.

So the time spent doing "guy stuff" as toddlers may pay off by helping them develop those hunting skills, Lonsdorf explained. Teachers of young children see some parallels to the way human toddlers approach learning.

"Boys at this age tend to be a little bit more playful, and the girls tend to be a little bit more grown up acting, and more responsible," said Tomi Hall, a kindergarten teacher at The New Century School in Atlanta, Georgia. "I can call on the girls a lot of times to do things that I know they will carry through and do, whereas sometimes I have to follow the boys around so they do what I've asked them to do."

Lonsdorf often gives public presentations to share her experiences. She said a lot of parents can relate to her study.

"A lot of them just laugh and say, 'I've got a boy and a girl, and what you describe in the chimps is exactly what I see in my kids,'" she said.

Observers say it is important to remember that there is no right or wrong way to learn, whether it's how to fish for termites or how to read, write and do arithmetic.

"Each gender may be innately better at certain tasks, but that doesn't mean that they aren't capable of trying any task," said Lonsdorf.

The Lincoln Park Zoo will soon open a new great ape exhibit, and a termite mound will be a part of it. At the Tanzania park, strict rules prohibit interaction between chimps and human researchers. But in Chicago, Lonsdorf said she'll be able to come up with some experiments to learn more about chimpanzees and their behavior.

Lonsdorf's research in the journal "Nature" suggests these gender-based learning differences may go back to the last common ancestor of humans and chimpanzees. And she said learning experiences are not the only things humans and chimps have in common: Both know how to have fun.

"The chimpanzees play 'airplane,'" she said. "They lie down and put the kid on their feet and fly them around, just like humans do."

The young chimps also like poking, tickling and having a great time.

"Sure seems like humans and chimps are part of the same big family," she said.
 

 They just can't help it

What kind of brain do you have? There really are big differences between the male and female brain, says Simon Baron-Cohen. And they could help explain conditions such as autism

Do you have a male or female brain? Take the test

Simon Baron-Cohen
Thursday April 17, 2003
The Guardian

Are there essential differences between the male and female brain? My theory is that the female brain is predominantly hard-wired for empathy, and that the male brain is predominantly hard-wired for understanding and building systems. I call it the empathising-systemising (E-S) theory.

Empathising is the drive to identify another person's emotions and thoughts, and to respond to these with an appropriate emotion. The empathiser intuitively figures out how people are feeling, and how to treat people with care and sensitivity. Systemising is the drive to analyse and explore a system, to extract underlying rules that govern the behaviour of a system; and the drive to construct systems. The systemiser intuitively figures out how things work, or what the underlying rules are controlling a system. Systems can be as varied as a pond, a vehicle, a computer, a maths equation, or even an army unit. They all operate on inputs and deliver outputs, using rules.

According to this theory, a person (whether male or female) has a particular "brain type". There are three common brain types: for some individuals, empathising is stronger than systemising. This is called the female brain, or a brain of type E. For other individuals, systemising is stronger than empathising. This is called the male brain, or a brain of type S. Yet other individuals are equally strong in their systemising and empathising. This is called the "balanced brain", or a brain of type B. There are now tests you can take to see which type (E, S, or B) you are. Not which type you'd like to be, but which you actually are.

A key feature of this theory is that your sex cannot tell you which type of brain you have. Not all men have the male brain, and not all women have the female brain. The central claim of this new theory is only that on average, more males than females have a brain of type S, and more females than males have a brain of type E.

So are females better at empathising? This theory rings true at an anecdotal level. For example, we've always known that people choose different things to read in the newsagent on the railway platform or in the airport departure lounge. Women are more likely to go to the magazine rack featuring fashion, romance, beauty, intimacy, emotional problems and agony-aunts, counselling, relationship advice, and parenting. Men are more likely to go to a magazine rack featuring computers, cars, boats, photography, DIY, sport, hi-fi, action, guns, tools, and the outdoors.

And we all have anecdotal impressions about typical hobbies for men and women. Men are more likely to spend hours happily engaged in car or motorbike maintenance, light aircraft piloting, sailing, bird- or trainspotting, mathematics, tweaking their sound systems, computer games and programming. Women are more likely to spend hours happily engaged in coffee mornings or pot-luck suppers, advising friends on relationship problems, or caring for friends, neighbours, or pets.

But the E-S theory goes beyond such anecdotal evidence to pull together the scientific evidence, and investigate the origins of these differences.

The evidence for a female advantage in empathising comes from many different directions. For example, studies show that when children play together with a little movie player that has only one eye-piece, boys tend to get more of their fair share of looking down the eye piece. They just shoulder the girls out of the way. Less empathy, more self-centred. Or if you leave out a bunch of those big plastic cars that kids can ride on, what you see is that more little boys play the "ramming" game. They deliberately drive the vehicle into another child. The little girls ride around more carefully, avoiding the other children more often. This suggests the girls are being more sensitive to others.

Baby girls, as young as 12 months old, respond more empathically to the distress of other people, showing greater concern through more sad looks, sympathetic vocalisations and comforting. This echoes what you find in adulthood: more women report frequently sharing the emotional distress of their friends. Women also spend more time comforting people.

When asked to judge when someone might have said something potentially hurtful, girls score higher from at least seven years old. Women are also more sensitive to facial expressions. They are better at decoding non-verbal communication, picking up subtle nuances from tone of voice or facial expression, or judging a person's character.

There is also a sex difference in aggression. Males tend to show far more "direct" aggression such as pushing, hitting and punching. Females tend to show more "indirect" (or "relational", covert) aggression. This includes gossip, exclusion, and bitchy remarks. It could be said that to punch someone in the face or to wound them physically requires an even lower level of empathy than a verbal snipe.

Two other ways to reveal a person's empathising skill are to see how they (as a newcomer) join a group of strangers, and to see how they (as a host) react to a new person joining their group. This has been cleverly investigated in children by introducing a new boy or girl to a group who are already playing together. If the newcomer is female, she is more likely to stand and watch for a while, to check out what's going on, and then try to fit in with the ongoing activity. This usually leads to the newcomer being readily accepted into the group. If the newcomer is a boy, he is more likely to hijack the game by trying to change it, directing everyone's attention on to him. And even by the age of six, girls are better at being a host. They are more attentive to the newcomer. Boys often just ignore the newcomer's attempt to join in. They are more likely to carry on with what they were already doing.

How early are such sex differences in empathy evident? Certainly, by 12 months , girls make more eye contact than boys. But a new study carried out in my lab at Cambridge University shows that at birth, girls look longer at a face, and boys look longer at a suspended mechanical mobile. Furthermore, the Cambridge team found that how much eye contact children make is in part determined by a biological factor: prenatal testosterone. This has been demonstrated by measuring this hormone in amniotic fluid.

All this adds up to a large amount of evidence for a female advantage in empathising, with at least some biological determinants. What about the claimed male advantage in systemising?

Boys, from toddlerhood onwards, are more interested in cars, trucks, planes, guns and swords, building blocks, constructional toys, and mechanical toys - systems. They seem to love putting things together, to build toy towers or towns or vehicles. Boys also enjoy playing with toys that have clear functions, buttons to press, things that will light up, or devices that will cause another object to move.

You see the same sort of pattern in the adult workplace. Some occupations are almost entirely male. Think of metal-working, weapon-making, crafting musical instruments, or the construction industries, such as boat-building. The focus of these occupations is on constructing systems. Professions such as maths, physics, and engineering, which require high sys temising, are also largely male-chosen disciplines.

Some psychological tests also show the male advantage in systemising. For example, in the mental rotation test, you're shown two shapes, and asked if one is a rotation or a mirror image of the other. Males are quicker and more accurate on this test. Reading maps has been used as another test of systemising. Men can learn a route in fewer trials, just from looking at a map, correctly recalling more details about direction and distance. If you ask boys to make a map of an area that they have only visited once, their maps have a more accurate layout of the features in the environment, eg, showing which landmark is south-east of another.

If you ask people to put together a 3D mechanical apparatus in an assembly task, on average, men score higher. Boys are also better at constructing block buildings from 2D blueprints. These are constructional systems. And in Nick Hornby's novel, High Fidelity, the male protagonist is obsessed with his record collection, and works in a second-hand record shop catering for (almost all male) customers searching for that one missing item in their collections of music. Collections (of albums, or anything else) are often highly systematic in nature.

The male preference for focusing on systems again is evident very early. Our Cambridge study found that at one year old, little boys showed a stronger preference to watch a film of cars (mechanical systems), than a film of a person's face (with a lot of emotional expression). Little girls showed the opposite preference. And at one day old, little boys look for longer at a mechanical mobile.

We, of course, know that with time, culture and socialisation do play a role in determining a male brain (stronger interest in systems) or female brain (stronger interest in empathy). But these studies strongly suggest that biology also partly determines this.

Some of the most convincing evidence for biological causes comes from studies of the effects of hormones. There was a time when women were prescribed a synthetic female hormone (diethylstilbestrol), in an attempt to prevent repeated spontaneous miscarriages. Boys born to such women are likely to show more female-typical, empathising behaviours, such as caring for dolls. And if a female rat is injected at birth with testosterone, she shows faster, more accurate maze learning, compared with a female rat who has not been given such an injection.

Some important lessons have been learnt from studies of clinical conditions. Male babies born with IHH (idiopathic hypogonadotrophic hypogonadism) have very small testes (and therefore low levels of testosterone) and they are worse at spatial aspects of systemising, relative to normal males. Other male babies born with androgen insensitivity (AI) syndrome (testosterone is an androgen) are also worse at systemising. Compare these with female babies born with CAH (congenital adrenal hyperplasia), who have high levels of androgens and who have enhanced spatial systemising.

But even if you leave aside these clin ical conditions, there is evidence for the effects of hormones on the mind in the typical child: our own study found that toddlers who had lower foetal testosterone had higher levels of eye contact. Presumably eye contact may have something to do with sociability and empathising. And a group of Canadian researchers found that the higher your prenatal testosterone the better you do on the mental rotation (systemising) test.

Should a theory like this be a cause of concern? Some people may worry that this is suggesting one sex is better than the other, but a moment's reflection should allay this fear. The theory is saying that, on average, males and females differ in what they are drawn to and what they find easy, but that both sexes have their strengths and their weaknesses. Neither sex is superior overall.

Others may worry that a theory like this stereotypes the sexes. But we need to distinguish stereotyping from the study of sex differences. The study simply looks at males and females as two groups, and asks why on average, differences are seen. There is no harm in that, and even some important scientific advances that can come out of it. Stereotyping, on the other hand, is when a characteristic of a group is assumed to apply to an individual, and this is potentially discriminating and harmful. The E-S theory does not stereotype. Rather, it seeks to explain why individuals are typical or atypical for their sex.

What are the potential new insights from a theory like this? It may help us understand the childhood neurological conditions of autism and Asperger syndrome, which appear to be an extreme of the male brain. Such individuals may have impairments in empathising alongside normal or even talented systemising. The theory also predicts the existence of the mirror-image of autism or Asperger syndrome, namely, the extreme female brain. Science has not even begun to investigate what such people are like, but we know they must have impairments in systemising, alongside normal or even talented empathising. Finally, the theory delineates two key dimensions of individual differences - empathising and systemising - that exist among any group of children, so that parents and educators can become more tolerant of difference.


Is there an explanation for autism?

I argue that people with autism may have an extreme of the male brain - good at systemising, very bad at empathising - and that studying autism with E-S theory in mind, can help increase our understanding of the condition.

Two largest sub-groups of autism are classic autism, and Asperger syndrome. Both share certain features: a difficulty in developing social relationships; a difficulty in communication; the presence of unusually strong, narrow interests; and a strong adherence to routines.

They differ in that in classic autism, the person might have an IQ at any point on the scale (even in the learning disabled range) and the person invariably had a language delay as a toddler. In Asperger syndrome, the person is always at least average in IQ (and may be well above average), and talked on time as a toddler. Autism spectrum conditions affect about one child in every 200, with males being far more likely than females to be diagnosed.

What's interesting is that the obsessional interests that people with autism spectrum conditions show often focus on a system. It may be an intense preoccupation with light switches in the house, or running water from the taps in different sinks in the house. For their long-suffering parents, these "obsessions" can be very hard to cope.

But according to the E-S theory the child may simply be focusing on the tiny details in the system - how fast the water flows when the tap is turned to different angles, or which lights go on when different switches are in the up or down position - using their intelligence to work out the underlying rules that govern the system. The characteristic approach they take is to home in on a topic or area of knowledge, and comb it for every detail, until they feel they've covered most if not all of the information available. The "obsession" might last weeks, months, or even years. And then typically, they move on to a new area to master.

Some parents and teachers will indulge the child so that the child can follow their obsessional interests all the way. And just sometimes, this can lead to great achievement or the development of expertise. Other parents or teachers - with good reason - feel a need to interrupt the child's obsessional focus. But the E-S theory sees individuals with autism spectrum conditions as having a learning style that prefers depth over breadth, and accuracy or exactness over gist.

So much for their strong systemising. What about their impaired empathising? This is the area that is likely to lead them into trouble, or to leave them disabled. Difficulty empathising translates into a whole set of hurdles. You might be last person to get the point of a joke, which can leave you feeling like an outsider. You might end up saying something that another person finds hurtful or offensive, when that was the last thing you intended. You might misinterpret other people's actions and motives. And you might just not pick up how others see you, and hence not know how you come across as odd or different. People's insincerity or subtle emotions may just go straight over your head.

Such difficulties can lead to a child with autism or Asperger syndrome being neglected, or even ostracised by their peer group. Or worse, teased and bullied. Tragically, such bullying often goes undetected by teachers and even parents, so that the child suffers in silence at school for years and years. During the teens, this difficulty in fitting into a peer group can lead the person with Asperger syndrome to become depressed.

No wonder educators are now urgently waking up to the existence of Asperger syndrome, since if it can be better recognised, many of these secondary difficulties might be avoided. And the hope is that a better understanding of such conditions - the extreme male brain - may lead teachers to be more tolerant of the very different learning style such children possess. If nurtured, systemising is not only a valuable contribution, but can even result in a refreshingly original way of thinking and seeing the world.

Simon Baron-Cohen is the director of the Autism Research Centre, Cambridge University. His new book, the Essential Difference: Men, Women and the Extreme Male Brain, will be published by Penguin on May 1 For more information, visit the National Autistic Society UK website www.nas.org.uk


Further reading
- Sex and Cognition, Doreen Kimura, MIT Press,1999
- Mindblindness: an essay on autism and theory of mind, Simon Baron-Cohen, MIT Press/Bradford Books, 1995
- Male, Female: The Evolution of Human Sex Differences, David C Geary, American Psychological Society, 1998
- The Two Sexes: growing up apart, coming together, Eleanor MacCoby Harvard University Press, 1998

Originally from: http://www.guardian.co.uk/life/feature/story/0,13026,937913,00.html
 

Tom Purcell
October 10, 2003

Michael Gurian has a radical idea: that men and women are different.

In his book, "What Could He Be Thinking? How a Man's Mind Really Works," Gurian, a therapist and social philosopher, cites decades of neurobiological research to demonstrate his point.

See, based on radioactive imaging and magnetic imaging, science is able to show that the male and female brain work very differently, which is why men and women are very different.

Take listening. One brain imaging study shows that men listen with only one side of their brain, whereas women use both. With all that interconnectedness going on, it's no wonder women remember everything we said from the moment they met us, whereas we can't remember what were we supposed to pick up at the store.

Another brain study shows that women can listen to two separate conversations at the same time, whereas men can barely follow one, particularly when it involves feelings or the spring sale at Bed, Bath and Beyond.

The male brain takes in less sensory detail than a woman's. That's why we don't notice dust, which apparently involves some kind of fine particles that settle on furniture. Men don't care about the inside of the house. We wired for larger spaces, such as the garage, the driveway, the yard.

Gulian concedes that the way humans are raised and nurtured does affect how we think and act, but the majority of what we are is driven by the way our brains are built. Emotions are a good example. The female brain secretes lots of oxytocin, a hormone that enhances the ability to feel emotions at a complex level, whereas we are driven by testosterone, which simplifies our emotions, particularly when they involve cocktail waitresses.

Despite scientific evidence that men and women are different, there has been a long push to pretend otherwise - to make men more like women. For more than 40 years, says Gurian, liberated women have been brought up to believe that it is men who have to change and men who must respond to the female way of doing things. And, boy, have women been successful.

Whereas male biological programming makes a man more interested in the outside of his house, today's metrosexual males are obsessed with their hair, their clothes and whether or not they should go with a mauve or taupe interior.

Whereas the basic wiring in men's brains direct us to be competitive and to demonstrate self worth by performing and providing for our families, most television shows portray fathers as bumbling idiots. Today's "progressive" fathers are cackling at baby showers and are the first to clap when junior does number two.

While men are embracing their more feminine sides, it is women who are doing all the things men used to. On television, it is the women who get into fistfights and demonstrate their self worth by mowing down the competition.

But Gulian tells us there's a much better way.

Instead of foisting preconceived notions on either sex about what we want men or women to be, why don't we use science to understand what we truly are. Gulian believes we're at a turning point as humans. We have a real opportunity to break free of the ideological shackles that confuse and complicate and hold us down.

Men, it's not a bad thing if our wives or girlfriends want to talk about the day's events. It's a show of affection. If we learned to listen more to what women are really saying, we'd be amazed at the level of thought and concern and consideration they put into most everything they do, and how it usually is a reflection of their love for us.

And, ladies, don't get upset when we mindlessly flip through the channels or do any of a million other mindless things that men do to relax. That's how we relieve stress so we can go out and perform and show our love to you. Hey, it's science.

But don't ask me, ask Michael Gurian. He's the one using neurobiological research to break new ground - to show that men and women are different.

I told you his idea is radical.

Tom Purcell is a nationally syndicated columnist. Other articles by Tom Purcell can be found in the MensNewsDaily.com archive.