Neurological Correlates

9 responses so far ↓

• 1 Ryan W. // Oct 21, 2009 at 11:04 pm

  There are a lot of problems with this; For starters, William Jennings Bryan, who prosecuted Scopes, was considered quite the top of his field. He was a brilliant lawyer, and few would argue that he was intellectually mal-adapted.

  Similarly, how well adapted are the corrolates of religious mindsets? Morality or social acceptability aside, if a person believes that homosexuality is wrong and people are supposed to procreate, will that person have more or fewer children. Especially in an age when sexually transmitted viruses look to wipe out a significant chunk of the African population. (I’ve actually always wondered how fertility correlated with homosexuality or bisexuality. I could see it going either way. So to speak.)

  Is promiscuity (in an age of birth control pills and STDs) adaptive or maladaptive compared to the belief that sex is for procreation only?

  And considering that a human’s environment doesn’t change substantially from place to place, why do humans even need much superior intelligence to adapt to a new locale? Don’t most of us in society free ride on the intelligence of others to begin with? Intelligence does not seem to be individually adaptive in modern humans.

  Finally, considering that the majority of believers in Evolution as well as most opponents of it don’t look too deeply into the evidence to begin with one wayand the question of origins has little impact on people’s day to day lives one way or another, why assume that the matter is indicative of a person’s general personality?

  In any case, I think that this assertion is a stretch. You’d need to start by demonstrating that there was general ‘inflexibility quotient’ or “IQ” that was an invariant property of those who believed in creationism, and not just conformity to a different social norm. This is especially true when ‘origins’ wasn’t the focus of someone’s education.

• 2 swivelchair // Oct 22, 2009 at 12:59 pm

  RW that is a great idea: an inflexibility quotient. The “intelligence quotient” (to the extent that is even a valid measurement of anything) is a proxy for synaptic plasticity because it measures the speed in which people learn. So the Inflexibility Quotient would be the degree to which synaptic plasticity is impaired.

  My point is this: intelligence or no, the ability to be a flexible thinker and learn new things is adaptive. IMO I think this is biologically based in synaptic plasticity to a large extent, but who knows, just a hunch. People who are synaptically not that plastic — like in the throes of substance abuse or having a neurofibrilliary tangle attack or cytoskeletal inhibition or some kind of tauopathy — have a tough time learning, and therefore a tough time in new environments. To grossly overgeneralize, people with social dominance orientation who lack the neural wiring for empathy probably fall in this category to some extent: social dominance in and of itself is sort of a short-term strategy. You get to the top and then the bottom crumbles out from underneath you. See, Financial Services Industry. (sorry for the digression)

  You query the premise and argue that there aren’t that many changes in new environments. Other people say things are moving too fast and changing all the time. But physical resources may or may not be negligible.

  As far as the religious “right” being possibly less synaptically plastic yet more evolutionarily advantaged because they profess to not practice risky sexual behavior, good point. To take to the extreme, if you are incapable of learning, but you never go out, then it’s probably a wash. It would be disadvantageous if the population stays closed too long and the double recessives start to come out (the Quakers have issues in this area, as well as some of the patrilineal societies in the Middle East for example). Kids are healthier when you don’t marry your cousin.

  Thanks for the comments RW

• 3 Ryan W. // Oct 22, 2009 at 1:41 pm

  So the Inflexibility Quotient would be the degree to which synaptic plasticity is impaired.

  I wonder about this, though. I mean, yes, sometimes people don’t learn something because they lack capacity. But sometimes people, even very intelligent people, don’t make certain connections because their ego interferes.

  My point is this: intelligence or no, the ability to be a flexible thinker and learn new things is adaptive.

  I don’t have the info for IQ in front of me, but don’t advanced degrees corrolate with decreased reproductive success? Especially for women? Female intelligence correlating with decreased birthrate, for instance, seems well established. I mean, I agree with what you’re saying if by adaptive you mean only individually adaptive and not socially or genetically adaptive. But it seems like you were hinting at genetically adaptive. It seems to me like evolution in modern times is tricky that way, since individually ‘maladaptive’ behaviors can actually lead to increased reproductive success.

  You query the premise and argue that there aren’t that many changes in new environments. Other people say things are moving too fast and changing all the time. But physical resources may or may not be negligible.

  Well, let me clarify; I was refering to the requirements for inhabiting new territory, since that was your animal model. Now, if “new territory” includes, say, a cubilcle at Google HQ you’re 100% right. It requires intelligence to get into that space. If it only refers to, say, living in Alaska then I’m not so sure. (Granted, there are higher IQ requirements for a cold climate. But it’s not enough to raise average IQ by even a full standard deviation.)

  Since you bring up inbreeding vs. outbreeding; I’ve often wondered about that. How often are recessives purely harmful, to the point that periodic inbreeding might be helpful? (Weeds out at least some lethal double recessives.) Or how often is the periodic harmful recessive actually adaptive as a recessive (resistance to malaria for the sickle cell gene, or mothers who can see in 4 channels of color who have sons who are better hunters due to different pattern recognition adaptations for their red green colorblindness.)

  . Kids are healthier when you don’t marry your cousin.

  What about grandkids from such unions?

  Best!

  Ryan

• 4 Ryan W. // Oct 22, 2009 at 1:55 pm

  To document a little of what I’m saying about ego preventing people from making connections when their intelligence was sufficient to do the logical reasoning;

  Consider Georges Lemaitre, the Catholic Priest who first did the calculations to support the ‘big bang’ theory. (A theory, incidentally, which was accepted quite early by the Catholic Church as consistant with scripture even while it received flack from more atheistic cosmologists such as Fred Hoyle)

  At this time, Einstein, while not taking exception to the mathematics of Lemaître’s theory, refused to accept the idea of an expanding universe; Lemaître recalled him commenting “Vos calculs sont corrects, mais votre physique est abominable”[4] (“Your math is correct, but your physics is abominable.”)

  To his credit, Einstein eventually changed course. But it took him a number of years to do so. I don’t think it’s going out too far on a limb to say that Einstein had certain views about how the universe worked that, while not consistant with a formal religion, were very much in vogue with academics of the time and thus essentially comparable to a religious worldview, and this contributed to his resistance to the Big Bang theory.

• 5 swivelchair // Oct 22, 2009 at 9:11 pm

  RW, interesting! OK, so we have to re-do evolutionary theory to fit my blog post.

  The trouble is that evolution — adaptation in the face of selective pressure — is a slidey thing. Context, context, context.

  Being of average intelligence, say, and having reproductive proficiency may be OK for a while, but when there’s selective pressure, then what?

  You could ask “what selective pressure?” and that’s a pretty interesting question: Socially aspiration is a selective pressure.
  It’s an abstract thing — not like “survives the plague” or “has healthy babies”. More of a social construct, but could be a selective pressure nonetheless. And, with a social construct rather than a physical one, seems like brain cell flexibility would be key to adaptability. (Yes the logic is tautological — neural flexibility is needed to adapt to new thoughts needing neural flexibility). So maybe my original premise — genetic frequency — is just outdated. The ability to get what one wants is the new currency for evolutionary success.

  But still. Aspiration as a social construct for selective pressure can change from generation to generation. So while physical strength may have been the aspirational value historically, being strong yet sensitive and still smell good (I kid) may be the aspiration in modern times. So you can have offspring with anyone, but you really want a mate that satisfies the “aspirational” selective pressure. So, the Google cubicle or corner office may be the aspiration — and so selective pressure would be that kind of intelligence and adaptability. So even with educated populations who have few offspring, if “selective pressure” is aspirational — could be that that’s the yardstick by which to measure evolutionary success.

  AS far as cognitive flexibility (or synaptic plasticity) the “ego” confounds the ability to adapt because it clogs up rational thinking — when you’re wrong about something the part of your brain indicating physical pain lights up in the scanner. With the “Big Bang” example — the Catholic Church, probably not wanting to go through the whole Galileo/Copernicus thing again, adapted the theory as being consistent with their teachings, although how a parsimonious “big bang” theory can mesh with scripture — that by definition includes divine intervention — is beyond me. (Sort of an oxymoron, “parsimonious scripture”, but whatever).

  In trying to figure out the neural pathway to “ego” perhaps it’s a form of “perceptual categorization. ” People neurally categorize things so with a new perception, the categorization is automatic. So when you see “black thing crawling up wall” even if you don’t see it closely, your brain puts it in the “eww it’s a bug” category, in a snap judgment. Probably the more educated one is, the more categories, and the more hardwired they are. Perhaps Einstein’s original rejection of the “big bang” not based on any facts was based on his cognitive inflexibility due to some sort of perceptual categorization. I’m guessing.

  On the double recessives: Lots of papers on Arab nations and problems with reproductive health among consanguineous populations but couldn’t see where it was advantageous, except in terms of social/cultural/financial advantages. Reproductive health is pretty much impaired after the first generation or two according to some studies, unfortunately.

• 6 Ryan W. // Oct 22, 2009 at 11:30 pm

  the Catholic Church, probably not wanting to go through the whole Galileo/Copernicus thing again

  You know, I’ve always thought that was funny as an example of religion vs. science. The Catholic Church was okay with Galileo saying; “the earth revolves around the sun in our models to simplify the math.” They just didn’t want him to present it as “fact.” Now granted, putting a guy under house arrest for a disagreement is terribly heavy handed, but I think it’s interesting that given relativistic physics, the Catholic Church was actually more accurate on that particular point (ignoring the whole ‘crystaline spheres’ and so on portion of pre-copernican theory) than many people readily acknowledge since there are no privileged frames of reference in relativisitc physics. As far as orbits (and not center of mass) are concerned in relativistic physics there is no ‘true center’ of the universe.

  So even with educated populations who have few offspring, if “selective pressure” is aspirational — could be that that’s the yardstick by which to measure evolutionary success.

  Success, sure. But evolutionary success? I don’t see how that fits. Evolutionary success = having lotsa grandkids. It’s objective.

  although how a parsimonious “big bang” theory can mesh with scripture — that by definition includes divine intervention — is beyond me

  It posited that the universe had a beginning and that the universe was created (contrary to the popular static universe theories of the day, which required no ‘creation’ event.) The bible was very helpfully vauge in describing just what ‘creating’ looked like. And considering that the OT later posited that God, for instance, used foreign armies to destroy Jerusalem it seems pretty clear that it’s fair game to describe a seemingly mundane act as ‘The Will of God.”

  Sort of an oxymoron, “parsimonious scripture”, but whatever

  I’m not sure I follow. Sometimes I think religion was seriously hampered by the fact that everything had to be fit onto short scrolls. … though sometimes I feel that’d be a good rule for modern lawmakers.

  Perhaps Einstein’s original rejection of the “big bang” not based on any facts was based on his cognitive inflexibility due to some sort of perceptual categorization.

  Could be.

  Though haven’t you seen what I’m talking about? I can’t remember the exact quote or original source, but it runs along the lines of “It’s hard to convince a man of something, if his job depends on him not believing it.” I’m not sure if that’s nessicarily related to intelligence or education, though it might be. I certainly believe that people can benefit from various rules or tools that help them when they’re seeing the situation based on what they want to seet, not what’s true.

  Re: double recessives. My point wasn’t to justify inbreeding indefinitely (.Though there is evidence that habitually inbred species actually suffer if they are outbred. ) My point was that periodic inbreeding followed by outbreeding may be better than consistent outbreeding for some purposes.

  Let me put it this way; lets say you make a punnett square for a brother and sister pair who are heterozygous for a lethal recessive gene. They can mate with each other, or with the outside population. Lets assume that the lethal recessive is mildly harmful but not fatal as a recessive gene (as is usually the case.) The result is more unhealthy children, but healthier grandchildren and great grandchildren because inbeeding for one or two generations weeds out lethal recessives.

  The Dominance vs. Overdominance page on wikipedia gives a differently worded explanation of what I’m posing; When is inbreeding followed by outbreeding better than consistant outbreeding? i.e. does inbreeding followed by outbreeding allow for ‘hybrid vigor’ allowing such individuals to be more fit than their great grandparents?

• 7 swivelchair // Oct 23, 2009 at 11:57 am

  RW I respectfully disagree:

  Evolutionary success = having lotsa grandkids.

  By that measure, cockroaches viruses have the best evolutionary strategy. But I think that misses the point.

  The trouble with reproductive proficiency as a measure of evolutionary success is that it doesn’t get to the point central to the purpose of evolution: adaptation in the face of selective pressure. Having lots of offspring is an indirect measure of successful adaptation. Large numbers of offspring are a hedge against dying out — an adaptation, rather than a result. Take nations where there’s generational starvation and blight — the strategy of having lots of offspring is a way to survive. The better way would be to overthrow corrupt governments and get local agriculture and cross-national trade, but you can’t do that when you’re starving . . .
  (So maybe it’s a temporal definition: after all, given a long enough time line, survival rate for everything drops to zero (to paraphrase from the movie Fight Club. . .))

  On hybrid vigor: An argument for human cloning, sort of. To get corn hybrid vigor, a corn variety is back crossed (self pollinating) 7 x and then breed with another variety. During the backcrossing, selection is for the best phenotype (which is expanded and used for the next round of backcrossing).This purges the deleterious recessive traits that come to the surface. So then when you take two “purged” varieties and cross them you can be pretty sure the hybrid vigor. Corn parent lines are pretty highly valued because of this, or at least they used to be before you genetic modification. If there were a way to clone yourself in both genders, then make sure that your cloned offspring would grow up and have offspring, that would seem to do the purge for people. (Wasn’t that a horror movie?)

  With patrilineal societies that have few “effective” males, the males seem to be purged for deleterious genetics. In a society where the males marry a number of females, males also tend to live in proximity to close relatives — siblings and cousins. So the males are genetically related — and the genetic effect is that that there are few genetically “effective” males. (Females, on the other hand, are from non-related genetic background and so there are many more “effective” females. )

  There may be an advantage to breeding against a known — and non deleterious – background as opposed to rolling the dice. But the whole thing is complicated by non-Mendelian genetics, like transposable elements and jumping genes and epigenetics and methylation patterns.

  “It’s hard to convince a man of something, if his job depends on him not believing it.” I

  The Aquatic Ape theory is posited to be because of that:
  http://www.ted.com/talks/elaine_morgan_says_we_evolved_from_aquatic_apes.html

• 8 Ryan W. // Oct 23, 2009 at 6:12 pm

  Sorry, the term I was looking for was reproductive success which does have the definition I gave it. (# of grandkids) It’s not the only objective measure of long term adaptability, but it does seem to be one of the best objective short term measures.

  I agree with part of what I think you’re getting at; that what makes a species (or population) go extinct may be different than what makes an individual reproduce or die. (Raup gives an interesting discussion of this in his book “Extinction.” His model argues that variation and the periodic stressors which maintain it is a crucial component of adaptability and thus length of species life. Dodos lived isolated form predators, and were wiped out when predators arrived. Raup gives, as an example of this, the average lifespan of sexual vs. asexual species. While asexual species (like dandilions) may be very prolific for a short time, their average species life is somewhere around 10,000 years compared to 100,000 years for sexual species. )

  The better way would be to overthrow corrupt governments and get local agriculture and cross-national trade, but you can’t do that when you’re starving . . .

  I’m curious; historically, which governments have become more fit after a revolution? Most true revolutions seem to leave society in far worse shape than beforehand. I’m thinking of Mugabe’s revolution in Zimbabwe as a particular example, or the Russian Revolution. Or Mao’s China. As corrupt as the KMT was, Mao seemed quite a bit worse in terms of # of people killed and the terrible devistation brought to China’s economy. The counterexamples of successful revolutions such as “The American Revolution”, for instance, were essentially conservative in that they maintained a great deal of the pre-existing power structure. So I’m not sure if violent internal revolution, at least as most people mean it, is the solution to corruption.

  Perhaps I’ve misunderstood you, though. Which country are you using as a model?

  This purges the deleterious recessive traits that come to the surface.

  Yeah, that was my point. To what extent does this “purging” happen during (temporary) human inbreeding? It seems like it must happen to some extent. Which would imply that periodic inbreeding could possibly be beneficial.

  With patrilineal societies that have few “effective” males

  I searched the linked article but couldn’t find the term ‘effective males’ in it. What constitutes an ‘effective male?’

  If there were a way to clone yourself in both genders, then make sure that your cloned offspring would grow up and have offspring, that would seem to do the purge for people.

  I agree, but Wouldn’t inbreeding accomplish something similar to what your describing? (It’s less effective, but also much more widely practiced) I’m not saying this is moral. I’m just discussing the expected effect of inbreeding, long term, followed by outbreeding vs. pure outbreeding.

  But the whole thing is complicated by non-Mendelian genetics, like transposable elements and jumping genes and epigenetics and methylation patterns.

  Oh, I agree. But I haven’t read anything which discusses in any detail how epigenetics applies to inbred popuations. Have you? It seems a rather new facet of genetics, with not much study before 2000 or so. At best, I’ve read stuff that suggests that in certain cases, outbreeding can cause problems because local adaptations don’t mesh well with the other population.

  Incidentally, it might be better to use animal models for inbreeding than humans. There are so many differing standards in data from different countries that it’s hard to compare apples to apples. There isn’t even a consistently applied definition for what constitutes a ’stillbirth.’ And death tends to be one of the things that is more consistently recognized across cultures.

  I’ve heard people reference the aquatic ape theory before, but hadn’t had enough of a chance to look into it. Thanks for the link. It makes sense. (The guy I talked to previously was talking about fat buoancy relative to animals like chimps or pigs, which didn’t check out at all. )

  Best,

  Ryan

• 9 swivelchair // Oct 27, 2009 at 2:25 am

  Hi RW,

  I agree with part of what I think you’re getting at; that what makes a species (or population) go extinct may be different than what makes an individual reproduce or die

  It’s how you define “survive” , because at any snapshot in time, one species or another may exist. My point was that reproductive success may not necessarily ensure survival in the face of a particular adaptive challenge. To paraphrase Cher, “after a nuclear war, the only thing left will be me and cockroaches”. Cher may not be numerous in spreading around her genes, but if she survives, she’s got a better chance than those who don’ t survive. (The whole analogy is off, I know, but I always liked that quote).

  What constitutes an ‘effective male?’

  Re: genders and “effective” population sizes (I’m not certain what you do not see? The “effective male” population is a derived term see, here (Wikipedia). As I understand it, the “effective” population for some demographic characteristic is calculable based on a bunch of presumptions that may or may not be correct, like haploidy.) In the paper, genetic diversity was measured as a function of gender. Here’s my blog post on it: “Population genetics: “You’re the reason why our kids are ugly” — how come more female genetic diversity in the gene pool? October 9th, 2008″

  So I’m not sure if violent internal revolution, at least as most people mean it, is the solution to corruption.

  RW, you have a good point about revolutions — Mao is Exhibit A. Mao is Exhibit A-Z. Paul Kagame is pulling Rwanda together pretty well, although I’m not sure that’s a revolution as much as a failed state from internal conflict. Perhaps failure to overthrow Mao will result in genetic ripples throughout the Chinese population for generations. Acute maternal stress during second trimester (here, the Israeli-Arab “Six Day War” in 1967) results in higher incidence of schizophrenia. Malaspina et al., “Acute maternal stress in pregnancy and schizophrenia in offspring: a cohort prospective study,” BMC Psychiatry 8: 71 (08.21.08)doi:10.1186/1471-244X-8-71 So you could even argue that revolutions are bad for producing evolutionarily successful offspring.

  But I haven’t read anything which discusses in any detail how epigenetics applies to inbred popuations. Have you?

  In one lab, inbred rats were found to be less prone to epigenetic changes than outbred:

  In his lab, he notes, inbred rats do not appear to show as big an epigenetic response as outbred rats, which are more genetically diverse. Skinner believes that outbred rats may have a bigger epigenetic response because they are generally more robust and vigorous than inbred strains. However, Robaire says that his demethylation experiments involving pharmaceuticals achieve the best results when he uses inbred rats. “Using inbred rats with the same genetics increases the signal-to-noise ratio and gives us better results,” he says.

  That was in a tox study. I guess it’s playing the numbers. If epigenetic changes are structure based (like the Cpg islands or whatever) then if you have diploid chromosomes, you’ll have the same pattern in each one. But, if each is different, then different patterns. (There was some debate and a paper retraction, so apparently the above study got off to something of a false start. . ).

  Incidentally, it might be better to use animal models for inbreeding than humans.

  An understatement. Epigenetic change seems to be a “surrogate end point” of adaptability.If adaptability is the measured quotient, then perhaps the degree to which epigenetic change happens, and the rate at which it happens, is really the measure of adaptability in a single person. The test subject wouldn’t have to be sacrificed for that.

  The guy I talked to previously was talking about fat buoancy relative to animals like chimps or pigs, which didn’t check out at all.

  I had heard about it a while ago, and I don’t know if you watched the video, but that scientists reminded me of Barbara McClintock who won the Nobel prize for “jumping genes” – transposable elements in plants — and was ignored. Now there are reports of people with transposable elements.

  Thanks for all your very considered comments!

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