Where are intelligence genes located


How does the brain work?
Is there a little difference?

After a lecture by Ms. Juniorprof. Dr. B. Liss, University of Marburg

We are all aware of the importance of the brain and its work for us. Without a brain we would not be able to think, feel and live. The brain is our most important organ. Although the brain only makes up two percent of our body mass, it consumes 20 percent of the total energy and is therefore the organ with the highest energy consumption. The brain processes information that runs over a nerve network of more than a hundred kilometers and has to be processed in 100 trillion synapses (connections between two nerve cells) at a speed that is 150 times the speed of ISDN. Above all, however, the brain is the organ in us that keeps giving us puzzles that humans have not yet been able to solve. The question of whether there is the "small difference" in the brain of women and men and whether one or the other is "smarter" was answered in this interesting lecture. What is certain is that there are differences in the fine structure between the female and male brain (e.g. hypothalamus). The fine structure of the brain is already influenced in the womb by the two sex hormones estrogen (female) and testosterone (male).

If you enter the term "female or male brain" in a search engine on the Internet, you will mainly find joking representations of both types of brain. The male brain is assumed to have mainly areas that are responsible for sex, football and beer. The female brain is more responsible for fashion and phone calls. But are these clichés just a coincidence? It is undisputed that men and women often think differently. In order to find these differences, tests were carried out in all cultures, in all age groups and in a wide variety of social environments. However, the results of these studies are only statistical and can only be applied to a large population. They cannot be transferred to a single person.

These tests showed that there are differences in the processing of information between the two sexes. Women are therefore better when it comes to, for example, perceiving details, solving arithmetic problems, practicing manual fine work or dealing with words. Men are more likely to have the ability to imagine things spatially, to carry out mathematical tasks, to carry out specific motor tasks (e.g. throwing and catching) or to orientate themselves spatially. Comparable gender-specific differences can also be found in animals. In an orientation test in a maze, for example, male rats performed better on average than female rats. In people who had undergone sex reassignment and were taking the corresponding sex hormones, a loss of former gender-specific skills and an improvement in skills that were typical of the new gender were often found. The main cause of these gender-specific differences in information processing are therefore the two sex hormones. If you think of the brain as a computer, the organ itself corresponds to the hardware and the hormones correspond to the software. It was also found that menstruating women often achieved better results than before in a spatial awareness test. During menstruation, the ratio between the two sex hormones changes and there is relatively more testosterone in the woman's blood.
So there are differences in thinking of both sexes, which are mainly influenced by the sex hormones. Of course, one must not forget that the upbringing of both sexes, which is often still different, is the cause of these behavioral differences.

But is one type of brain more efficient, i.e. more intelligent, than the other?

In order to determine the intelligence of a person, certain intelligence tests were developed. A so-called intelligence quotient (IQ) can be determined from the result of these tests. The average value for this is 100. If you have an IQ of 130 you are considered highly gifted, if you have an IQ of 70 or less you are considered weak-minded. It was once suggested that men are more intelligent because the male brain has on average a larger volume than the female brain. But this thesis is wrong because both women and men have an average IQ of 100.

More interesting, however, is the claim that intelligence is female, since women have two chromosomes and men only one X chromosome. It has been proven that there are three times as many genes that are responsible for intelligence on the X chromosome than on all other chromosomes. On the (male) Y chromosome, which the man has instead of a second X chromosome, there are no "intelligence genes" at all. But what are the consequences for "female and male intelligence"? If a woman has a defective or particularly good "intelligence gene" on one gene on an X chromosome, this predisposition is balanced by the other corresponding gene on the second X chromosome. In men, a special system on the X chromosome shows through without correction. As a result, women tend to have an intelligence average (100 IQ) and men tend to have more extreme IQ values. So there are more feeble-minded and gifted men than women. Nevertheless, this claim that intelligence is female is also wrong.

So there are small differences between the male and female brain, but these are more related to the sex hormones. Although neither of the two brains is "smarter" than the other, there are different dispositions of information processing. However, it would be wrong to conclude from this that a man can generally park better than a woman, since tests have shown that, on average, men have a better spatial orientation than women. The rule that men and women have different skills can only be applied to a very large population and is confirmed by exceptions.

Patrick Dingel, high school diploma in 2004




Tobias Meinel, Grammar School Philippinum, Leopold-Lucas-Straße 18, 35037 Marburg,
Tel .: 06421-931805, Fax: 06421-931804 | Last updated: November 14, 2004
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