May 2008

The Differences Between Men And Women

When I was told I had one of the papers at the "open session" (read mixed company), I began to wonder what topic might be both of interest and appropriate.  My previous papers on languages generally drew polite yawns, even from the men; and my one on profanity seemed ... well, not boring but a bit misplaced.  Then I thought how are men and womwen are alike? What interests do they share?  But the more I thought, the more I realized that the essence is not in similarity but in difference.

As Lerner and Lowe put it: Why Can't A Woman Be More Like A Man? Or... is a woman different from a man?  Tonight I would like us to explore the gender gap, if indeed it exists.

I won't fill the night with unsubstantiated old saws like men being innately better at math or women at writing poetry. So I have restrictrd myself to more or less objective studies.

Serious subjects, and I suppose it's moot whether this is a serious subject or not, often are expressed in jokes. And like aphorisms, jokes can drive home a point.

	For example, it has been said that women want one man to satisfy their every need; men want every woman to satisfy their one need.
	Or consider the time a man was driving down the road with his window down, and a woman standing on the roadside yelled, "Pig!"  The man yelled back, "Bitch!" and then ran right into a huge pig in the middle of the road.

        Woman's joke: What do you call a man who is sensitive, good-looking, rich, and powerful?  A rumor!
        Man's joke: A blond (incidentally, this term is often code for "a woman in general") began crying. "What's wrong?" her husband asked. "The doctor just called that my mother has died."  He was consoling her when the phone rang again. The blond answered and then began crying even louder.  Again her husband asked what was wrong now. "That was my sister, and here mother just died too".


      Gender differences create a certain tension, men control the channel flipper, women the shopping. But there is another conflict inherent in gender differences. 

      The jargon "cognitive dissonance" refers to one sort of conflict better illustrated than defined. A person smokes. Smokers die much more often of lung diseases than do nonsmokers. How does the individual cope with such cognitive dissonance?  Similarly, feminists are faced with their conviction that there are really no differences between men and women and that therefore they should be treated the same.  But the same feminists are confronted with all sorts of objective data to the contrary, facts difficult to ignore. Let's look at differences established by careful research and not by chauvinistic speculations.

Physical Differences
	In utero a fetus viewed by sonogram looks pretty much the same, excepting the genitalia, whether male or female. Even after birth little boys and little girls, if you except the society-laden factors like types of toys or blue versus pink clothing, are a lot alike. (Incidentally, research shows adult males prefer the color blue and females red!)

        Then comes puberty, and all bets are off. From then until death the differences are obvious.
	
      To get the facts on physical disparity I turned not to my medical texts but to the armed forces. According to military statistics, 68% of men can lift 110 pounds but only 1% of women.  Upper body strength differences are considerably greater than lower body ability.  In the 1997 New York Marathon the median woman ran 11% slower than the median man.  Women are twice as likely as men to get multiple sclerosis, migraines, and rheumatoid arthritis.  Lupus and fibromyalgia are 9 times more common in women. There are physical differences. Women have a 78% greater chance of becoming blind. Men are four times more likely to die of a smoking-relarted illness, but women have about caught up with men in lung cancers.

                The brains are different.  Dr. Sandra Witelson, neuroscientist at McMaster Univ. in Ontario, found that the corpus callosum, that bridge between the two sides of the brain, larger in females. AND the right brain area used for symbolic analysis was bigger. Men's brains overall ARE bigger, but women's have 11% more neurons, esp. in 2 of the 6 layers of the cortex. Women have more white matter, the place neural connections occur. 
 
Where does physicality end and behaviorism begin? Deborah Blum in her book Sex On The Brains: The Biologic Difference Between Men And Women, asks the reader to imagine an island where all children are reared as girls until puberty. Then half are reared as male. Such a thought experiment might help distinguish between nature and nurture at least insofar as sexual identity was concerned. Well, in fact such a situation occurs  in a few Dominican villages where there are genes causing stunted penises and undescended testes in the males, who therefore resemble females anatomically. At puberty those actually males develop beards and almost normal male anatomy and behave as normal males.
                For some time it has been known that prenatal testosterone levels determine finger length, specifically the ratio of the second to fourth digit ratio.  In men the ring or furth finger is typically longer than the index.  In 2007 Tester and Campbell of Durham University in England measured four personality traits and one type of cognitive ability (mental rotation) that are all thought to be linked to sports achievement. There was a good correlation between sports ability and digit ratio. Perhaps you saw this reported on national television, where the researcher successfully predicted the order of finish of runners from just their digit ratios.

And if there are real physical differences, what about behavioral differences. And are such differences inate or learned?
	Folk wisdom says men think of sex every minute, women every few days. It is said that men use 7000 words a day vs women's 20,000!
      But do women really talk more than men? In the journal Science last year Tuscon resarchers reported voice recorders worn by 396 subjects for several days. Both men and women spoke about 16,000 words a day. 

        And how do the sexes interreact with other human beings? Dr. Ruben Gur, director of the Brain Behavior Lab at the Univ. of Pennsylvania School of Medicine (Science 1/27/07) showed happy or sad faces to male and female subjects. Men and women did equally well at identifying the mood of happy pictures, but men could spot only 70% of sad women faces versus 90% of sad men faces.

	Since my days in medical school we have a marvellous new tool that, in a sense, lets us see what people are thinking, or at least what part of the brain is doing the thinking.  Magnetic resonance imaging or MRI is what I mean. Positron Emission or PET scanning shares features of this. So we can explore behaviorism using PET scans or functional MRI to detect metabolic activity in parts of the brain under experimental conditions. The part of the brain that lights up metabolically or the part that lights up from increased blood flow is by assumption the part that's doing the thinking.  So ....

		Dr. Sally Shaywitz, a behavioral scientist at Yale Medical school and her husband, Bennett Shaywitz, a neurologist there, performed functional MRI on 19 men and 19 women as they read nonsense words and decided whether or not they rhymed. Men's brains lighted up in a region near Brocca's speech area, in the left temporal part. Women showed activity there plus in a region of the RIGHT brain.
                Don Burman at Northwestern University used functional MRI on 62 children aged 9 to 15, half boys, half girls. They were exposed to two words at a time, some pairs flashed on a screen, some spoken to them. They were to determine whether the pair was spelled similarly omitting the first letter (like "pine" and "line") and whether the words rhymed (such as "gate" and "hate" as contrasted with "pint" and "mint").  Some of the pairs met neither criterion, such as "jazz" and "list".  The brains of girls showed greater activity than those of boys in the "language areas", that is in the superior temporal gyrus (a part used to decode words), the inferior fronta gyrus (speech processing), and the fusiform gyrus (spelling and meaning). For girls it did not matter whether the words were seen or heard.  That group is now checking to see whether the gender gap closes in adulthood.

		Louann Brizendine, neuropsychiatrist and author of The Female Brain, found that talking activates the pleasure centers of teenage girls' brains more than any stimulus ...  except orgasm.

		Ruben Gur, mentioned before, in Science 1-27-07, showed that, at rest, men and women's brains looked more or less the same on MRI, but with stimulation men showed more activity in the primitive or action area of the limbic system while women showed more in the symbolic-activity section or newer limbic area. The primitive brain lights up with attacking, the newer brain with showing your fangs.

So much for imaging studies. Are there differences in performance testing?  We all know men are better at math and women at poetry? Right?

                 In 1999 C. W. Hall and colleagues at East Carolina Unversity studied 5th and 8th grade student scores on math tests, the California Achievement Test math concepts and math computation sections. There were no significant gender differences.

                 And using another California test, the Verbal Learning Test, Kramer and assciates looked at 401 boys and 410 girls ages 5 to 16. Sex differences were seen at all levels, with girls outperforming boys on immediate and delayed recall and on delayed recognition. Interestingly, the two groups were given the WAIS for children, and the boys had mean higher IQ scores than the girls. Thus, female superiorty in verbal learning was not attributable to intellect alone.

                 And it seems to make a difference whether testing the two sexes involves tasks close at hand to the subject (peripersonal space) as opposed to the same tasks in extrapersonal space.  Saucier and others from Canada reported in 2007 that women excel in tasks near at hand and men in tasks located further away using the Object Location Memory Task.

                  Deloache from U. Va reported in Developmental Psychology last year a study of the intense chldhood interests in 177 subjects. Boys were much more likely to show intense interests than girls.

                  Quickly here are some other behavioral differences: When it comes to food selection, men prefer meat and poultry, women fruits and vegetables. Women prefer almonds, walnuts, eggs, yogurt, apples, strawberries, raspberries, and blueberries.  Men are more likely to eat asparagus and brussel sprouts. Men prefer frozen hamburger patties, women fresh hamburger. These fingdings were reported at the 2008 Conference on Emerging Infectious Diseases in Atlanta.

                   When it comes to suicide, men are three times as likely to go that route.

                   When it comes to television viewing, men favor news and sports, women safety, natural disasters, and "tabloid" exposes. Network morning news attracts 28% of women but only 17% of men, nightly network news appeals to 31% of women and 25% of men, but local news attracts the sexes about equally. Asked if they read the newspaper yesterday, 38% of women said yes and 44% of men. 

Well, so much for the externals, physical and behavioral disparities.  Are there genetic or chemical differences?

                  The sexes handle drugs differently. Women have 30% more adverse drug reactions than men. One of the most serious reactions to drugs involves a disruption of normal heart rhythm and can lead to death.  It is called torsades de pointes from the EKG appearance of twisting points and occurs more frequently in women than in men. The reason is unknown, but part of the difference may lie in a litle chemical processing plant built into people called cytochrome P450, subtype CYP3A4.  This little machine is more active in women than in men, and it is one of the ways humans activate or eliminate drugs. But CYP1A2 is more active in males.

                  Women have less body water (52% vs 61% on average), and so there is less dilution of alcohol in women even for two people of the same weight.  Wherefore recommended allowances for alcohol are lower in women.

                  The sexes handle cancers differently, at least some types of cancer. Worldwide female melanoma patients outsurvive males. From the Netherlands last year de Vries and friends reported 10,538 patients with melanoma. At any given time after diagnosis a man had a 1.87 risk of death compared to females with tumors of matched body site, size, etc.

So there are objective gender differences. Wouldn't life be boring if there weren't?  But what conclusions can we draw about the differences?  I fear that neat packaging of gender differences into one grand explanation would be a bigger job than the unified field theory. As the French say, although I searched the Web in vain to find the phrase's original use, "Vive la difference!"