Slashdot Mirror
Size Does Matter... But Only in Women
Frankenmoro writes "This online article at Nature notes that new research indicates that a woman's intelligence is directly related to the size of her brain. But, before you uber-male-geeks start to gloat, it may be that a woman with half your brain size has the same language processing power as you do, seeing as how you only use half of your brain to process language, and she's using it all... Lazy boy."
Was there any correction for the BMI (body mass index) of these women? Larger people have larger cranial vaults and thus have room for larger brains.
What is the correlation between pre-mortem CNS volume and post-mortem CNS volume?
What was the age at death of these women? (I know the article states that, unlike men, womens' brains do NOT shrink with age, but the distribution of ages could have played a role.)
What was the self-selection index in these women? How were they chosen to be in the group of women whose brains were donated to science? Were they organ donors (a very small pool) or were they cancer victims (a much larger pool) who were approached to enter this study?
As to some of the other comments so far, even though I don't believe I.Q. is an accurate measure of intelligence, it is at least a fixed quantitative measure of performance on an I.Q. test. Kinda like the SATs: they just measure how well you perform on the SATs.
A person's sex, as we all have noticed, tends to affect the size of that person's body. Men, of course, tending to have the larger frame, also have the larger average size skull. As much as people would like to dismiss this truth, their continues to be a correlation between an individual's skull volume and that particular individual's intelligence as measured by a variety of tests. The strange thing about these findings is that while men with larger skulls tend to be of greater intelligence than men with smaller skulls, and women with larger skulls tend to of greater intelligence than women with smaller skulls, men, as a group having larger skulls, do not tend to be of greater intelligence than women, who as a group tend to have smaller skulls. (that was quite a sentence.) It seems to be the case that women have a greater concentration of "computational" neurons than men, and that men have a greater concentration of "transportational" neurons in any given section of the brain. These neurons could be thought of in terms of processors and memory chips being the computational variety and the transportational neurons being the wires that provide for their communication. These transportational neurons, used for transmitting messages over comparitively larger distances in the brain are of obvious use to men, whose larger neural network require more interconnections in comparison to run at an efficient speed. Women who have been endowed with a larger than average skull manage to avoid the genetic instructions that require resources to be given to the wires rather than the chip, seem to make out with greater computational power, possibly at the expense of a negligable amount of speed.
I want to add my two cents on this IQ debate. Simon and Chase and Simon did a number of studies on chess players in the 70's. Give an expert a chess position - s/he can memorize the entire board in one look. Give it to a novice chess player, s/he can memorize just a few pieces. THEN they gave the experts and novices RANDOM positions (pieces just mixed up everywhere) and there was no difference in ability to remember the position. Both the experts and novices were unable to remember more than a few pieces. The explanation is that experts have deep and complex schemas which they use to memorize large patterns and relational structures on the chess board. When they cannot use them, they are in the same position as a novice. Carry this over to the IQ test. Someone who is a mathematics expert will be able to memorize far more numbers in a random string than someone who is an expert in poetry for the same reasons mentioned above. Basically the IQ test is a test of expertise in an extremely limited range of subjects chosen mostly for historical reasons I guess.
Second point. Someone said that humans are not naturally "rational" or words to that effect. Absolute rubbish! First of all what do you mean by "rational"? If you will accept my (and others) definition of "rational" - which is roughly ability to engage in logical reasoning ala the "scientific method" then humans are innately rational. Humans engage in hypothetico-deductive reasoning all the time just in order to function. Read Anton Lawson (1993) in Cognition and Instruction, for complete explanation.