You know that stupid story about inheriting your intelligence from your mother, that I debunked? Emily Willingham said pretty much the same thing, so now you can trust that I was right.
This is not surprising, and it didn’t require a conspiracy or telepathy or a Vulcan mind meld — it was a totally bogus claim that anyone with any significant biology training at all would have found mind-bogglingly inane.
In the same way, scientists around the world are groaning upon hearing Attenborough’s aquatic ape fannishness, and for the same reason — it’s patently false.
I don’t have any biology training, significant or otherwise, but I would have guessed it was bogus. Of course, I’ve been reading a certain mid-western biology professor’s blog for several years, and I’ve learned a little bit like…it’s all very complex and any claim about “one gene” is automatically questionable.
Also, you should view any science journalism with a skeptical mind regardless of who produced it, particularly for unusual claims a la wet apes.
Some folks get so tied up with a bogus idea they loose track of any perspective. In both cases in the OP, it went against years of reading about science by real scientists. Not that hard in such situations to step back and say “show me the evidence”, and watch the handwaving and jawing instead of the pointing to the literature.
Regarding the proposition of mostly inheriting one’s intelligence from one’s mother, I remember hearing about this years ago.
Women typically have two X chromosomes, & men typically have an X & a Y, & the Y is puny compared to the X, Could it be that women, more so than men, can pass on a better quality X? If that is the case, & if significant numbers of genes “for” intelligence reside on the X, then it may be the case that intelligence is preferentially inherited from mothers.
Has anyone ever looked at the offspring of academic mothers & labourer fathers, compared to academic fathers & labourer mothers, to see if there are inherited differences in intelligence between the groups. Possibly, that’s where the original proposition came from?
There is no such thing as intelligence genes, and no, women do not pass on better quality X genes than men do. Just because one person is an academic and the other a laborer does not mean the academic is more intelligent. I make more money cleaning toilets than the biomedical researcher with their Ph.D., which one of us is smarter?
Tethys, genes code for proteins, which result in our morphology. This includes brain structure & chemistry, which affect intelligence.
On average, I would think it highly probable that academics tend to be more intelligent than labourers. My own observations support this hypothesis, despite individual exceptions. Academics are usually in academe for knowledge rather than just for money.
Cleaning toilets is important too.
I would say rather that academics are better educated than laborers. Until we have some kind of way of measuring something accurately that we can objectively define as intelligence we are only measuring outward academic achievement. Having been a laborer in construction and in industry I can say that there are some very smart laborers out there and as the saying goes there are others who could not find their own ass with both hands. I dare say there are more than a few “academics” you could say that about as well.
uncle frogy
unclefrogy:
Yes, but all else equal, people who have an aptitude for being educated will tend to be better educated than those who do not, and intelligence is positively correlated with learning.
Which has nothing to do with the OP.
Anyway. Dick’s purported point is vacuous not only because the link between intelligence and occupation is much more dependent on circumstance than on intelligence, but because occupation is “heritable” only in a social sense, not a biological one.
Let me summarise the claim without detracting from its merits:
“genes code for proteins, which result in our morphology. This includes brain structure & chemistry, which affect intelligence” → “On average, I would think it highly probable that academics tend to be more intelligent than labourers.” → “Cleaning toilets is important too.”
(Heh)
Just for the record, I recognize that getting off to a bad start at kindergarten, or not living in a home where books are valued, can send a child on a trajectory not conducive to academic achievement. i also recognize that an individual’s intelligence is malleable, (whatever intelligence might be).
As an engineer, I’ve mixed both with academics and labourers, (as well as engineers). Under different life circumstances, the high achievers might have failed, & the low achievers might have succeeded. But come on folks, get real! Some people are born with an innate intellectual advantage over others, regardless of circumstance.
that is just the point in most things I have tried my hand at there was often a lot that could be learned about how to do it. There was always a smart way to work and a not so smart way to work.
and from the other thread
if all of that could be sorted out we might have some thing but until then not so much
uncle frogy
I for one am not saying anything different but I do not think however that picking anything as arbitrary as academic achievement as a stand in for intelligence or “intellectual advantage” will get you there how ever.
uncle frogy
Don’t forget that one of the female X chromosomes came from a male. The history of any X chromosome zigzags between males and females. They also recombine during meiosis so gametes get hybrid X chromosomes, part from the father, part from the mother.
What is a better quality X? Without any idea or way to measure, this isn’t meaningful. The chromosomes get distributed randomly during gamete formation, with rare special cases not relevant here.
dick, I accept your opinion as such, but I give it little weight.
Well, yes — but that’s a triviality. It’s a property of anything with a probability distribution.
Going from that to implying that toilet-cleaners are probably
more stupidless intelligent than academics needs some sort of justification, other than that is it’s what “On average, I would think”. Some consideration of possible confounding factors would not go astray, either.(And to pre-empt Nerd, some citations :) )
As an anthropologist, I’ve had engineers tell me that Aliens™ built ThePyramids.
and that Men have one fewer rib than Women because Adam and Eve
.
get real! Some people are born with an innate intellectual advantage over others
PS Dick,
Kudos; quite a concession, if detrimental to your thesis about the purportedly implied significant linkage between intelligence and occupation.
(As for intelligence, the current psychometric variable is the g factor)
This is a frustrating medium. In my post @ 3 I wondered if there might be a possible mechanism that could cause intelligence to be preferentially inherited from mothers.
I don’t know how chromosomes recombine, & what the consequences might be.
Only Raven has addressed that; everyone else is nit-picking on some perfectly reasonable statements.
I understand that women are less susceptible to various genetic defects than men, because they possess (usually) two X chromosomes. It seems to me that that this could have an impact on capacity for intelligence.
dick #15
Which statements were ?
dick:
Why do you focus so upon intelligence? Independence, stubbornness, perseverance, resilience, etc etc. Do you imagine that their application significantly less effective than is g in determining success within any given milieu?
(BTW, if you imagine more copies of X are better than fewer, perhaps consider Klinefelter syndrome; as the story goes, the porridge should not be too hot or too cold, but juuust right)
I don’t think people have found any simple thing like this which correlates strongly with intelligence. Where did it come from? Someone may have have pulled the hypothesis out of their ass. Who knows? But it sounds like you’re imagining that there was some actual empirical result to talk about, not just a hypothesis. Maybe there was some such result — aren’t you supposed to be pointing us to it so we can evaluate that on its merits, instead of merely speculating that something of that sort possibly happened?
Then why even ask about X and Y chromosomes? You do or you don’t know about something which is supporting your hypothesis? If it isn’t involving that or about that, then what is it?
You’re an engineer, so give me an idea of how an intelligent human is built. What kinds of materials are needed, what kind of processes have to occur, etc. Go step by step, and don’t leave and of the steps out.
If I were just throwing out random guesses that possibly somebody at one time did a (probably dubious) study about how to build bridges out of jello wrapped in tinfoil, the first thing you might want to ask me is whether I know anything about bridges or how they are built. Or if anything else which is at all useful could be made out of jello wrapped in tinfoil, maybe you’d want to know what that is and how it relates to bridge-building.
If I just throw up my hands at that point and say I have no clue, you could very safely ignore my bullshit. Maybe somebody else will come along a do a better job, without the bullshitting — so your pet idea may still be persuasive some day, just not when the conversation goes like this.
So maybe you don’t know about any of these bridge-building studies. Perhaps you reply by claiming certain bridges are better/more durable than others. I’m going to agree because I can make similar observations. But this doesn’t help us. It’s perfectly reasonable to point out that this kind of fact doesn’t go anywhere to support the claim that some of the bridges are made of jello wrapped in tinfoil, or that wrapping jello in tinfoil had anything whatsoever to do with the construction process. It’s just a plain old non sequitur.
Maybe you understand this, but I don’t. What “various genetic defects” are you talking about, and how do you know they’re connected in some way to X or Y chromosomes?
Is “capacity for intelligence” the same thing as intelligence, or do you mean something like a potential which may not be actualized, for some other set of reasons that we’re leaving out of the analysis? If the latter, what exactly would we be looking for that comes in the form of a “potential” something? What is “an impact on capacity for intelligence”? … however it seems to you and whatever that is, tell me something a little less vague that will give me an idea of what specifically is supposed to seem that way to me.
It would help to use less “could” and “maybe” and “possibly” — anyway, nobody is going to be ruling any such things out as logically impossible. So when these claims are rejected (or supported, for that matter), you shouldn’t take them as rejections of that sort, since the issue is about contingent facts (what they are, as far as we know, given the evidence we have, and so on).
With respect, dick, you’ve wandered into a discussion having neglected to read the material linked to in the OP which would have answered many of your questions, and you’ve inserted opinions that seem very close to genetic elitism only to call them “trivial” when people object to them (if these statements are so trivial, why bring them up int he first place and why defend them?).
But since you asked a question, here’s my attempt at an answer:
X chromosomes from women are not superior or inferior to X chromosomes from men. They are the same thing. Without getting into complex detail about the genetics of sex (it’s a lot more than just XX=female, XY=male), the basic story is that women inherit two X chromosomes, one from each parent, while a man inherits one X chromosome from his mother. And a man with one X chromosome necessarily passes that one X to any daughter he has (as opposed to sons, who get a copy of his Y). Which means that the daughter then has the X chromosome from the father, which he in turn got from his mother. I’m sure you can see that this means that over several generations, there is really no difference between X chromosomes from men and women. The Xs all get shuffled about in the population.
The only significant difference between male and female X chromosomes is that the normal process of chromosomal recombination can only work for the X chromosome in women because they have two Xs, while for men there is no second X so no recombination is possible. But this makes no difference to your scenario because (i) recombination is random, it does not make chromosomes any better or worse overall, and (ii) for the reasons stated above, the X chromosome recombination still takes place in women and then gets shuffled through the population, including men, over time. A man’s X chromosome can’t go through recombination in his own body but his X came from his mother, where it *was* subject to recombination.
After so many decades of eugenics, failed genetics to provide that “super intellect” or even above average strength, we’d think that the “superior gene” bullshit would’ve died off.
Nope! People slap on a new coat of paint and ignore the rust under it.
Chris, @ 19, thank you for addressing my question. I thought that the random shuffling of (portions of) X chromosomes that you described was the likely process.
However, natural selection, if it could act upon beneficial effects of having two Xs, would do so. It didn’t seem inconceivable to me that a process might evolve of selecting the better X (causes higher survival & reproduction) if there are two to choose from.
I realize now that this doesn’t happen, because there are genetic diseases that do get passed on despite both parents getting two copies of all the other chromosomes (except Y).
And I don’t have a eugenics agenda!
I suspect faulty extrapolation of colorblindness into a similar intelligence gene (faulty in two ways: {1} assuming the similarity, {2} assuming the very existence of the latter)
from http://www.colourblindawareness.org/colour-blindness/inherited-colour-vision-deficiency/
similar to eye-color dominant/recessive genes. The CVD (color vision deficiency) is also recessive gene.
Also apparently overlooked in the discussion is the inactivation of large portions of one of the X chromosomes during the formation of Barr bodies. Most females have only one fully active X chromosome.
@ 22 slithey tove
There are in fact over 100 X-linked genes in which inactivating mutations are associated with intellectual disability. According to wiki they account for about 16% of all intellectual disability in males. However none of these genes show linkage to variation in the range of intelligence.
machineintelligence
This is inaccurate. There is only one active X in each somatic cell. Women with two X chromosomes deactivate one of them, which results in a Barr body. Which X is deactivated is entirely random for most placental mammals. For people with more than two X genes it is even more complex. (from the wiki on Barr bodies)