Tuesday, September 25, 2018


A test to predict Alzheimer's?

This finding is not terribly surprising. Verbal ability is the biggest single component of IQ and mechanical ability is quite highly 'g' loaded too.  And we have long known that high IQ people have better health across the board.  So finding that people who are bad with words are more likely to develop Alzheimer's fits with that.  It's another part of the syndrome in which IQ is an index of general biological fitness

A test given to hundreds of thousands of students, including rock stars Janis Joplin and Jim Morrison, nearly 60 years ago could hold the answers to whether a person will develop dementia.

Researchers at the Washington-based American Institutes for Research, which administered the test to some 440,000 high school students across the US in 1960, have been studying the teen's answers and believe they have found a link to student's who scored low on the test and Alzheimer's disease.

According to the Washington Post, researchers compared results for more than 85,000 testers with their 2012/2013 Medicare claims and expenditures and found that warning signs of memory loss may present itself as early as adolescence.

The study found specifically that those who scored low on mechanical reasoning and memory for words had a higher risk of dementia later in life. Researchers found that low-scoring men were 17 per cent more likely to get dementia, while low-scoring women were 16 per cent more likely.

The test, called Project Talent, was administered to high school kids from 1,353 public and parochial schools across the country. It was funded by the US government.

SOURCE 

Friday, September 14, 2018



That "leptokurtic" really is important

Grumble, grumble.  In my attempts yesterday to explain why the distribution of female IQ is narrower than for males, I approached it from the wrong angle.  I followed Ted Hill's approach and tried to explain the male distribution rather than the female distribution.  That was crazy and I want to point out why.

The normal or Gaussian distribution is a mathematical construct which shows most instances of anything as being clustered around the mean (average).  A remarkable thing about it, however, is that most natural phenomena tend to scatter in that pattern.  The normal distribution really is normal!

A normal distribution is however rather "fat".  It covers a fair range.  There is a pic of one below



And male IQ follows that pattern fairly closely.  The female IQ does not quite follow that pattern, however.  It is leptokurtic, meaning narrower.  It is not so spread out. See the example below:



So we don't have to explain the male distribution.  It is normal.  What we have to explain is why the female distribution is narrower. And that seems fairly easy to me.  No algebra is required! As I said yesterday, men are very uniform in what they like in a woman.  A lot of it is physical: Long legs, a slim figure, some bosom, long hair etc. If a lady with those characteristics is kind to a man he will be in love! And high IQ in a woman is not a big priority for men. It may even be a negative for some.

So women have evolved to maximize the fairly narrow range of things that men like, with other characteristics falling by the wayside -- including IQ.  Men have made women less varied.  Won't the feminists like to hear that!

So how does male selectivity explain the low frequency of really dumb women?  That is pretty straightforward.  Men require some minimal level of IQ in order to find a woman attractive.  So women below that level will not mate and not reproduce.  Men have also set the lower bound of female intelligence

So how do we account for the fact that dumb men seem to proliferate without restriction?  Should not the general female preference for high IQ cause such men to die out? I dealt with that yesterday but I think I should repeat my remarks here for the sake of convenience. 

The fact that low IQ women are often FAT comes into it a lot in our society but the handicaps that low IQ women have will of course vary from society to society.

In summary, I think we have to conclude that quite dumb men can still be of some use to some women. How?  In all mate selection, what you will overlook as well as what you get is important. And some women will apparently overlook low IQ.  I suspect that it is a simple case of similarities attracting.  Low IQ women will be attracted to low IQ men even if the IQ levels are not exactly the same.  Low IQ women take what they can get in order to reproduce and low IQ men get some acceptance that way.  The very strong female urge to have babies drowns out other considerations. And that is in fact one thing we do clearly know about low IQ women:  They do have lots of babies.  And it is their babies that pump up the low IQ male population

So we have to look not only at what men and women like but also what they will do without.   I remember a related phenomenon well.  I have done a lot of things in my life and I once ran a large boarding house in a poor area.  It was very instructive in a number of ways, not all of them bad. 

And one thing I remember is the partnerships I observed among my clientele and their friends.  In particular, I observed that even pumpkin-shaped women had partners.  Fat is a huge social handicap so how did they manage that?  By being very tolerant, by overlooking a lot.  Their partner might be a boozy, smoky, scrawny loser but he was a male -- and the pair did seem to be reasonably supportive of one-another most of the time.  Both were aware of their low level of attractiveness and felt glad to have someone, anyone, in their lives of the opposite sex.

UPDATE: 

A reader offers another explanation:  "I believe the simple explanation for the narrower range of females in general is to do with the XX chromosomes they have. There are relatively less genes on the male Y chromosome than the X.  In many cases this means men have nothing to balance any bad genes on the X Chromosome they get from their mother. Basically this means men get to throw one die whereas women get to throw two.  The distribution reflects this"


Thursday, September 13, 2018



The leptokurtic distribution of IQ in women is due to sexual selection

OK.  I will translate that into plain English.  The academic article below has become immensely controversial because of foolish feminist attempts to suppress it (They have in fact assured it of widespread attention) -- so I will just try to translate the controversial part.

For a start, I disagree with the article.  I think it assumes what it has to prove.  It starts with what may be a true premise: That women in general are fussy maters.  They are much more fussy than men about who they will partner with long term. That's the "sexual selection" part.

And the "leptokurtic" part refers to the fact that female IQ scores tend to be bunched around the average, with few very dumb women and few very bright women when compared to men.  That's the bit that fires feminists up with rage. That there are fewer women than men at the top of the IQ range is totally against their ideology.  They are, however, barking at the moon in their rage -- because the leptokurtic distribution of IQ among females has been found repeatedly for around 100 years.  It is as firm a finding as any in science.  It is a fact and no objecting to it will make it go away.  So they are wasting their breath in condemning it.

But, given the finding, where do we go from there?  The theory below is heavily mathematical and I cheerfully admit that I am a mathematical dunce.  I get by but only barely. So, maybe I have got the theory below all wrong, but what I get from it is that women will only accept the upper end of male desirability.  Low desirability males will never find a reproductive partner.  The theory then goes on to assume that desirable men come from a more varied distribution and that mating with them will reinforce that varied distribution.

That seems nuts to me.  As far as I can see, the only effect of women discriminating heavily in favour of desirable men should be to raise the average level of desirability.

The authors below set out their basic premise as follows:

"In a species with two sexes A and B, both of which are needed for reproduction, suppose that sex A is relatively selective, i.e., will mate only with a top tier (less than half ) of B candidates. Then from one generation to the next, among subpopulations of B with comparable average attributes, those with greater variability will tend to prevail over those with lesser variability. Conversely, if A is relatively non-selective, accepting all but a bottom fraction (less than half ) of the opposite sex, then subpopulations of B with lesser variability will tend to prevail over those with comparable means and greater variability"

So I think their very starting point is wrong.  Where they say: "those with greater variability will tend to prevail over those with lesser variability", I would say that "variability will gradually decline".  I would be delighted if someone could explain where I am wrong.

So let me set out my own theory. It also has its difficulties, as we will see, but I think it explains more.  It seems to me that although some women are very picky -- to the point of not finding a mate until they are past childbirth -- they are very diverse in what they are picky about -- which is something of a Godsend for us men.  It gives hope to us all.

Although there are some things that are generally popular among women -- tall, well-built men with smooth skin tend to have an easy ride -- there is a variety of views in women about what is important.  Some women, for instance rather despise the "Jock" stereotype and go for more "sensitive" men. And a really big factor in mate selection is getting similar levels of IQ. Few women can tolerate a man who is dumber than them, for instance.  They mostly want one who is as bright or brighter. They may be unaware that they are looking for intelligence but the things they do consciously look for are often correlated with higher intelligence -- higher income, better education, better health  etc.  And lots of "defects" will be tolerated by a high IQ woman if that is the only way she can get a high IQ man.  That is my theory about how I managed to get married four times!

A man, on the other hand, is much more uniform in what he likes in a woman.  A lot of it is physical:  long legs, a slim figure, some bosom, long hair etc. If a lady with those characteristics is kind to him he will be in love.

So, in sum, my simple theory is that men are more diverse than women because women are more diverse than men in what they will accept in a mate. And a lot of women like a higher IQ in a man, whereas high IQ in a woman is not a big priority for men. It may even be a negative for some.

My theory would even account for men being taller.  If you have ever got to know short men to any extent you will be aware of how irate they are that most women look right over their heads.  That makes them determined that their sons will not be so "handicapped".  And the only way they can have tall sons is to get a tall woman as a mate.  So they go all-out for that, regardless of most other criteria.

It ends up that you often see a dapper short man with a rather odd looking lady -- but one with long legs.  If a woman is tall she will always be able to get a mate -- even if he is a bit short.  So there is heavy sexual selection for tallness in men.  Female long-leg genes get attached to whatever genes short men have.  Short men tend not to have short sons

But now we come to the difficulty I alluded to at the outset.  How do we account for the fact that DUMB men also proliferate?  Should not the female preference for high IQ cause such men to die out?

I think we have to conclude that dumb men are of some use to some women. How?  In all mate selection, what you will overlook as well as what you get is important. And some women will apparently overlook low IQ.  I suspect that it is a simple case of similarities attracting.  Low IQ women will be attracted to low IQ men even if the IQ levels are not exactly the same.  Low IQ women take what they can get in order to reproduce and low IQ men get some acceptance that way.  The very strong female urge to have babies drowns out other considerations. And that is in fact one thing we do clearly know about low IQ women:  They do have lots of babies.  And it is their babies that pump up the low IQ male population

So we have to look not only at what men and women like but also what they will do without.   I remember a related phenomenon well.  I have done a lot of things in my life and I once ran a large boarding house in a poor area.  It was very instructive in a number of ways, not all of them bad. 

And one thing I remember is the partnerships I observed among my clientele and their friends.  In particular, I observed that even pumpkin-shaped women had partners.  Fat is a huge social handicap so how did they manage that?  By being very tolerant, by overlooking a lot.  Their partner might be a boozy, smoky, scrawny loser but he was a male -- and the pair did seem to be reasonably supportive of one-another most of the time.  Both were aware of their low level of attractiveness and felt glad to have someone, anyone, in their lives of the opposite sex.

And in case what I have just said sounds too derogatory, I must also note that they were all fairly pleasant people, at least while sober.  They had a relaxed attitude to life that many smarter people could well learn from.

There is however a remaining difficulty in my theory. What I have so far proposed would seem to imply that the male offspring of low IQ women will take after their father while the female offspring of low IQ women will take after the slightly higher IQ of the mother.  But it doesn't work like that.  Children can take after either parent.  So am I back to square 1 in explaining the lesser variance in female IQ?  It looks like it.  My theory accounts for a lot but something more is needed.

Abstract only below.  Full article at the link



An Evolutionary Theory for the Variability Hypothesis

Theodore P. Hill

Abstract

An elementary mathematical theory based on “selectivity” is proposed to address a question raised by Charles Darwin, namely, how one gender of a sexually dimorphic species might tend to evolve with greater variability than the other gender. Briefly, the theory says that if one sex is relatively selective then from one generation to the next, more variable subpopulations of the opposite sex will tend to prevail over those with lesser variability; and conversely, if a sex is relatively non-selective, then less variable subpopulations of the opposite sex will tend to prevail over those with greater variability. This theory makes no assumptions about differences in means between the sexes, nor does it presume that one sex is selective and the other non-selective. Two mathematical models are presented: a discrete-time one-step statistical model using normally distributed fitness values; and a continuous-time deterministic model using exponentially distributed fitness levels.

SOURCE



Only dummies use drugs

Forgive the over-simplified heading above.  I have clearly been reading too much journalism. What the article below shows is that illegal drug use is greatest in people who did poorly at school. Sadly, the authors are better at using complicated statistics than they are at thinking.  The BIG determinant of academic achievement is IQ, and yet they do not even mention IQ, let alone control for it.  They have wasted their efforts by that omission.  Low IQ would have caused both the low academic achievement and drug abuse.  The study tells us NOTHING new and skips over what was actually going on.  Sad and pathetic

Academic Achievement and Drug Abuse Risk Assessed Using Instrumental Variable Analysis and Co-relative Designs

Kenneth S. Kendler et al.

Abstract

Importance:  Low academic achievement (AA) in childhood and adolescence is associated with increased substance use. Empirical evidence, using longitudinal epidemiologic data, may provide support for interventions to improve AA as a means to reduce risk of drug abuse (DA).

Objective:  To clarify the nature of the association between adolescent AA and risk of DA by using instrumental variable and co-relative analysis designs.

Design, Setting, and Participants:  This study, assessing nationwide data from individuals born in Sweden between 1971 and 1982, used instrumental variable and co-relative analyses of the association between AA and DA. The instrument was month of birth. Co-relative analyses were conducted in pairs of cousins (263 222 pairs), full siblings (154 295), and monozygotic twins (1623) discordant for AA, with raw results fitted to a genetic model. The AA-DA association was modeled using Cox regression. Data analysis was conducted from October 2017 to January 2018.

Exposures:  Academic achievement assessed at 16 years of age (for instrumental variable analyses), and estimated discordance in AA in pairs of monozygotic twins (for co-relative analyses).

Main Outcomes and Measures:  Drug abuse registration in national medical, criminal, or pharmacy registries.

Results:  This instrumental variable analysis included 934 462 participants (478 341 males and 456 121 females) with a mean (SD) age of 34.7 (4.3) years at a mean follow-up of 19 years. Earlier month of birth was associated with a linear effect on AA, with the regression coefficient per month equaling −0.0225 SDs (95% CI, −0.0231 to −0.0219). Controlling for AA, month of birth had no association with risk of DA (hazard ratio [HR], 1.000; 95% CI, 0.997-1.004). Lower AA had a significant association with risk of subsequent DA registration (HR per SD, 2.33; 95% CI, 2.30-2.35). Instrumental variable analysis produced a substantial but modestly attenuated association (HR, 2.04; 95% CI, 1.75-2.33). Controlling for modest associations between month of birth and parental educational status and DA risk reduced the association to a HR of 1.92 (95% CI, 1.67-2.22). The genetic model applied to the results of co-relative analyses fitted the observed data well and estimated the AA-DA association in monozygotic twins discordant for AA to equal a HR of 1.79 (95% CI, 1.64-1.92).

Conclusions and Relevance:  Two different methodological approaches with divergent assumptions both produced results consistent with the hypothesis that the significant association observed between AA at 16 years of age and risk of DA into middle adulthood may be causal. These results provide empirical support for efforts to improve AA as a means to reduce risk of DA.

SOURCE