Controversial BBC IQ gender report

[Martin]

http://news.bbc.co.uk/1/hi/education/4183166.stm

 

the article appears to have gotten a lot of attention on the internet because it is highly controversial---makes people angry at the IQ tests used because they favor males slightly, and so on

 

lots of difficulty interpreting what it all means, if anything, and lots to discuss

 

no difference reported up to age 14 (is this a mating display thing like the peacock's tail that evolved because females were attracted to show-off intelligence? ---- seems to appear with puberty)

 

if it is real, that is

 

were the researchers bad people motivated by a desire to get results like this? one of the commenters complained that they did not also show results that also more criminals and such are men, "for balance".

 

speaking of tails the only really large gender differences they discovered was in the hi-IQ tail, like over 125 and over 155.

 

so, anyway, there it is. It is news (came out thursday) about a scientific study, and it is fiercely controversial, and we can probably learn as much from reading the comments, where people responded, as from the main text.

 

have fun and don't shout

[Martin]

http://news.bbc.co.uk/1/hi/education/4183166.stm

 

 

Well this news item looks like a complete dud!

 

Somebody publishes a study saying men are smarter than women and no one bats an eyelash. Ho hum, this is what we knew all along?

 

5 IQ brighter on average

 

and twice as many men as women at the 125 level.

 

an earlier SFN thread on this topic:

http://www.scienceforums.net/forums/showthread.php?t=14077

 

question was, if the difference found by the study is real, and has a genetic basis, how could that genetic difference have evolved?

[LucidDreamer]

It could have something to do with sexual selection. Today, and through most of the history of man, woman are most highly valued for their looks while men are valued for their intelligence and achievements. So any mutation of the genome that resulted in a high intelligence for somebody with a XY chromosome pair would have been more advantageous than developing that same degree of intelligence in the XX pair.

 

So it could work like this: Jennings, a well-known researcher of IQ, says that man has an allele for intelligence called the g-factor that when present gives the person an IQ of 130 or more. Perhaps the g-factor allele is present on the X chromosome and it is more expressive when it is exists in a single copy with the XY pair. So woman that have one of the copies of the g-factor allele express some of the g-factor intelligence, but they also express some of the phenotype from the other allele, so the overall expression of the g-factor is not as pronounced. Furthermore it could be that when woman have two copies of the g-factor that they end up with only approximately the same expression of the g-factor phenotype that the men with a single copy have.

 

This could result in what we see with this research where a lot of women tend to be in the middle, because it is common for woman to have one copy of the g-factor and one of the other allele.

 

The genotypes of woman would be (A=g-factor allele and B=non-g-factor allele: 1/4 AA with a full g-factor expression and an IQ of 130 or over, 1/2 AB with a partial g-factor expression with an average IQ, 1/4 BB with no g-factor expression and a below average IQ.

 

Men’s would be (O=the absence an allele because X is a single copy in men): 1/2 AO with full expression of g-factor and an IQ of 130 or over, and 1/2 BO with no g-factor expression and a below average IQ.

 

Since only 1/4 the woman have the full expression of the g-factor and 1/2 the men have full the expression, this could result in the results where twice as many men have an IQ over 125 that you mentioned.

 

The puzzling thing about this is why don't you notice the difference until after the age of 14? It could be that a certain amount of accumulation of knowledge and experience with problem solving, combined with a maturation of the brain is necessary to initiate the changes in phenotype that we see with these results. It is known that there are several periods of brain reorganization during the growth of children where a certain amount of brain cells are actually sheared off and the it is believed that these events actually result in a more efficient brain that is especially adept at performing functions that the child has practiced many times. It could be that the last major reorganization, which occurs around the age of 13, is partly controlled by the g-factor allele.

 

There are so many problems with the theory that I just stated. Just a few are the fact that the g-factor allele and the non-g-factor allele would probably not be present in the population in a 50/50% ratio, saying that these studies are related to the g-factor which is in turn related to the XY chromosomes which is in turn related to brain reorganizations is quite a stretch. The main problem is pretending that these studies might have any validity. It isn’t know exactly how much IQ is related to intelligence. These kinds of studies can be manipulated so much that they have no meaning. There are so many social factors at work here that its hard to separate what is actually due to genetics and what is due to social factors.

[swansont]

the article appears to have gotten a lot of attention on the internet because it is highly controversial---makes people angry at the IQ tests used because they favor males slightly' date=' and so on

[/quote']

 

 

How do you demonstrate that this is bias, though? Is it assumed that the tests favor men because they score higher, or is it that the tests are fair (with regard to whatever qualities for which they are testing), and men score higher?

 

I think that IQ tests measure something, but defining what they do measure is tough to determine. I also think it's a bit funny that people get all upset when one gender test differently than the other - there are differences between men and women. Why wouldn't this manifest itself in general differences in mental abilities? I think the issue is the interpretation that different somehow means better or worse, depending on context.

[Martin]

I will copy a post of Skye's from the other thread where it was #8:

 

 

 

 

if that is the case then one might ask how such a situation could have evolved?

 

One thing it could be, to add to your list, is that because men could have more children than women, then positive traits will be given greater reward. A really successful man could have many more children than a really successful woman. This assumes a certain amount of choice in partners.

 

The interesting thing is that it mightn't be a matter of men being intrinsically smarter but of women providing greater care to their sons. This isn't too far fetched as it normally takes more effort anyway, men take longer to reach maturity and are bigger.

[Martin]

Here's post #9, interesting one from Shen Zhou, whom I hadn't encountered before

 

 

There are more disorders associated with XY than XX because XX has gene redundancy.

 

There is also a disproportinately large number of genes on the X chromsome that affect mental function. The X chromsome makes up about 3.7% of the genome but 27% of genetic diseases with mental retardation are X liked:

 

see this paper: X-linked genes and mental functioning. David H. Skuse. Human Molecular Genetics' date=' 2005, Vol. 14, Review Issue 1

 

"Why should there be such a concentration

on this particular chromosome (1)? Zechner et al. (2) suggest

that the X-chromosome has been engaged in the development

of sexually selected characteristics for at least 300 million

years and that natural selection has favoured the development

of X-linked genes that are associated with higher cognitive

abilities. In particular, males are more likely than females to

be influenced by haplotypes that are associated with exceptionally

high abilities. For an equivalent reason, they are

also more likely to show deficits in mental abilities than

females because of the impact of deleterious mutations

carried in haploid state. The hypothesis offers an explanation

for the higher male variance in many aspects of cognitive

performance"[/quote']

[Martin]

Looking again at what ShenZhou said:

"Zechner et al. (2) sugges tthat the X-chromosome has been engaged in the development of sexually selected characteristics for at least 300 million

years..."

 

IF THIS IS TRUE WHAT OTHER PREDICTIONS CAN ONE MAKE ABOUT GENES ON THE X? WHAT OTHER THINGS BESIDES INTELLIGENCE as measured by that test in the UK study ARE SEXUALLY SELECTED CHARACTERISTICS IN HUMANS and might reside on the X? or on the Y, instead of elsewhere?

 

"...and that natural selection has favoured the development

of X-linked genes that are associated with higher cognitive

abilities..."

 

WHY WOULD NATURAL SELECTION FAVOR genes for higher cognitive function THAT ARE X-LINKED? Why wouldnt those genes be just as likely to reside on other chromosomes, not X and not Y? The implication of what ShenZhou quotes is that higher cognitive characteristics are SEXUALLY SELECTED. Why would that be? What selection mechanism. Naively one would think that whatever the IQ test measures would be equally useful to males and females alike.

 

OK ONCE WE GET A SITUATION WHERE HIGHER COG GENES ARE LOCATED ON THE X, THEN ONE CAN SEE WHY THEIR EXPRESSION COULD BE MORE VARIABLE IN MALES SO THAT YOU SEE MORE SPREAD. SO THE REST OF THE QUOTE FROM SHENZHOU MAKES SENSE:

 

"...In particular, males are more likely than females to

be influenced by haplotypes that are associated with exceptionally

high abilities. For an equivalent reason, they are

also more likely to show deficits in mental abilities than

females because of the impact of deleterious mutations

carried in haploid state. The hypothesis offers an explanation

for the higher male variance in many aspects of cognitive

performance"

 

Does this mean that we have to go read Zechner et al? Does that article spell things out more clearly?

[Martin]

BTW it is interesting that the 5 point IQ difference only shows up at age 14.

 

Does something happen to females at age 14 that makes them do worse on this particular test?

Or conversely some physiological or chemical change in males improves their ability to do whatever the test measures? And could this be a purely emotional or motivational thing (the females could score just as high if only they wanted to or had a more positive self-image or something)?

 

And then why should this 5 point difference in the average score persist throughout life? One would think that if it is just an emotional or motivational or social thing affecting 14 year olds, that the effect would diminish later on. The permanence seems to point to a physiological change.

 

No women have responded on this thread.

[SorceressPol]

No women have responded on this thread.

 

It's hard to comment on this subject. I have no idea what my IQ was at fourteen. I was a late bloomer' date=' so I got the emotional stuff when I was seventeen. At fourteen I didn't really care about what I looked like so my self image never affected the way I tested on anything. Maybe the women who had their growth spurt around 14 may have had troubles testing. ::shrugs::

But I agree with the comment below that I found.

 

 

Originally posted by Ryokan

The way I understand it, men have a higher average IQ, and women a higher median IQ. Men are more likely to be extremely intelligent, or extremely dull. SO while on average men are smarter than women, your average man is dumber than your average woman.

[Thomas Kirby]

A lot of women simply aren't taught the sciences, which IQ tests favor.

[Martin]

It's hard to comment on this subject. I have no idea what my IQ was at fourteen. I was a late bloomer' date=' so I got the emotional stuff when I was seventeen. At fourteen I didn't really care about what I looked like so my self image never affected the way I tested on anything. Maybe the women who had their growth spurt around 14 may have had troubles testing. ::shrugs::

...[/quote']

 

Pol thanks so much for replying. We don't seem to have gotten much discussion on the topic this time round.

It would be really rather dense of us to see this as a "Who's better?" issue and get our egos involved. If the result had turned out that Females after age 14 scored 5 points higher than Males I would be asking exactly the same question.

if this 5 point difference is partly genetic then how did it evolve?

AND HOW DID IT EVOLVE IN SUCH A WAY THAT IT DOESNT SHOW UP BEFORE AGE 14 AND THEN GETS SWITCHED ON?

 

It is called a "dimorphism" I think. Sex-linked dimorphisms evolve under various kinds of selection pressure, can probably happen by random drift, but one ought to be able to exclude that on a casebycase basis where unlikely.

 

I didnt hear of MALE RATS being more able to solve mazes. I have the hunch that FEMALE ELEPHANTS are actually more savvy and learn things faster. maybe someone knows about this. I do not. And any book on falconry will tell you that FEMALE FALCONS are preferred for hunting because the female falcon is considerably bigger than the male. But here is this one species---human---where there is this peculiar spread, look at it from the point of view of an outsider of another species that visits this planet. Why?

How did this come about?

 

Well Skye offered an idea or two, and Shen did. but that is about it.

So maybe that is all SFN says about this at least for the time being, and we just move on.

 

we can always come back to this thread later if someone gets an idea, or learns of some new result.

[Germanium]

perhaps we are being a little too scientific here. It is only 5 points higher on average, and i don't think its something that warrants another battle of the sexes. Its probably just chance... like independent assortment in meiosis!

[Martin]

perhaps we are being a little too scientific here. It is only 5 points higher on average, and i don't think its something that warrants another battle of the sexes. Its probably just chance... like independent assortment in meiosis!

 

I think I share a part of your perspective. I am bored by "battle of the sexes" talk----whatever the results, they shouldn't make female egos bristle or male egos gloat. Although if people are irritated, or if they want to challenge the validity, or say it wasnt nice to investigate in the first place, then they should feel free to indulge in "battle of sexes" discussion.

 

but suppose that a bunch of us, you, I, others look on the result as neutral---we are non-human organisms from another planet who don't identify with human male-female polarity and we see this as just another curious set of facts about Terra life-forms

 

then how do we evaluate it? is it interesting or not? is there anything about it that piques your curiosity and requires explanation?

 

I hear you saying that the results are NOT of much interest-----to discuss reasons might well be "too much science"----giving them more attention than they deserve.

 

I disagree with that part of what you say, and will try to persuade you there are some things that could use explaining (and might contribute to understanding human brain genetics better)

 

1. It is not just the 5 point difference in average.

 

"...As intelligence scores among the study group rose, the academics say they found a widening gap between the sexes.

 

There were twice as many men with IQ scores of 125, for example, a level said to correspond with people getting first-class degrees.

 

At scores of 155, associated with genius, there were 5.5 men for every woman."

 

2. The 5 point different between the averages didn't show up until age 14

 

I guess it is the second thing that arouses my curiosity. If the results are real and not just bad research, then what could it be that "turns the difference on" abruptly at age 14?

 

But I think I can also understand your feeling that it would be "a little too scientific" to try to explain these things. Certainly are a lot of equally or more interesting puzzles in human genetics---and in the universe at large!

[SorceressPol]

I looked up some sites, and some popped up stating that most mental illnesses start at age 14, at least in America. Would that have any contributions to the IQ test results?

 

http://www.coolnurse.com/mental_healthusa.htm

[Martin]

I looked up some sites' date=' and some popped up stating that most mental illnesses start at age 14, at least in America. Would that have any contributions to the IQ test results?

 

http://www.coolnurse.com/mental_healthusa.htm[/quote']

 

hi Pol! so nice you are still dropping in on this thread. I am in the slightly awkward position of WANTING to hear some discussion around these things but not being able to reply helpfully to people's questions because I dont know enough.

 

I would suspect that your idea is right and that it DOES have something to do with that abrupt change in the IQ testscores by a small amount. but cant say what.

 

BTW it is really hard for me to imagine that testosterone flooding the system could have a beneficial effect on the brain. it would seem to me generally antagonistic to cognitive faculties, but I could be wrong.

 

and adolescent male birds do seem to get some brain development connected with singing ability about that time-----do birds do testosterone?