The squirrel example is absolutely absurd - there are clear physiological, morphological differences between human beings and squirrels that influence whether or not squirrels even have the capacity to master fire, or whatever other silly comparison you choose. Furthermore, I think you will find that environmental factors plainly influence the behavior of animal populations (squirrels, chimpanzees, birds - any kingdom, genus or species you choose) far more than any particular genetic variation among them - animals of the same species without abundant resources behave quite differently from animals of the same species in an environment of abundance (one need only look at any pest species - animal or plant - to see that this is true).
There does not exist much variation across 'societies' of animals within the same species - one tribe of baboons is much like another tribe - but there exist vast gaps between societies of human beings, so far as these gaps influence the environment of individuals among populations, and entire populations as a whole.
There is no physiological model for human intelligence, and since only physiological traits are inheritable (though psychological traits may be derived from morphological differences) there is no model for genetic influence on intelligence. Since there is no model, you can only blindly test a black-box hypothesis - and the results from those tests appear to support the conclusion that there does not exist any inheritable, physiological difference that would influence intelligence, controlling for societal factors.
I don't think it's absurd, I only think initially that it was wishful thinking, now I see that it was only a poor example to a good idea that he explained later.
Yes intelligence has to do with heritability, there was initially an animal with had cognition (a word I much prefer instead of intelligence) this animal actually had descendants some of which are humans, we initially inherited this intelligence from him but also from other ancestors that developed this cognition latter as well.
You provided that we do not have a physiological model for intelligence, and I believe we will not have one for some decades at least if I'm to be optimist. That's a real large problem, another one is to relate this to genetics and environmental development, these would be a hard problem as far as I was told by some friends that are biologists.
My point regarding not having a model was to bring the genetics/environment statistics onto the same footing - the black box statistical evidence does not accept that genetics is a factor in measures of intelligence, but does accept that environmental factors such as income and health are.
I would also add, that the political agenda is not from those advancing the idea that environment influences human development, but from those that contend it is genetics.
Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor - why would you support development for poor populations of people if it was found that they simply don't have the same development potential? You would simply screen for the 'genius' gene and push the rest of society toward a supporting role.
In the case of the environmental view, you must now implement policies that raise the living conditions for the majority of people in society - better and more schools, better and more social programs, better opportunity - that's expensive, and there's not much money to be made.
"Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor..."
You have somehow completely missed and then parroted back my entire point. If it turns out that genetics plays a key role in intelligence, and therefore intelligence is hereditary, all sorts of nazi-like policies could be theoretically be falsely argued for using that as evidence. Seeing this obvious conclusion, some in the scientific community have become crusaders, trying to squash any debate or research into this topic, making it taboo.
Being taboo, or having very negative or even awful potential consequences doesn't make something true or untrue. The universe doesn't care that the consequences of some fact are moral or immoral.
I am not saying the truth is one way or the other. I am pointing out the willingness on the part of some scientists to refuse to allow investigation because of the potential consequences of knowledge of the truth.
What I see sometimes in these discussions is people throwing the "hot potato" in the hands of their detractors, people that believe in the difference between groups throw the potato in the hands of the disbelievers and accuse them of being obtuse for trying not to advance an "obvious truth".
The other side just answer by accusing the others of being "racist".
The fact is the data is poor for a significant statistical analysis and for some reason this research has become heavily politicized, this in academia is a good enough reason for some people just ignore this entire field, but I never saw people trying to prevent this type of paper from being publicized or peer reviewed, last time I searched there's various being published every year.
How can you say "that's an unfair accusation." and then in the next line say "The other side just answer by accusing the others of being "racist"."
I agree that there is no consensus, and no evidence that clearly helps determine the truth here. That is why I said it was an "unanswered question" in GGP.
However, we do have some ability to reason about this. Clearly genetics can play a role in intelligence. We don't know if it does between humans, but we do know that it could. Humans are very abnormally (as successful species go) genetically similar, probably because of various population bottlenecks.
So, it could go either way. It is quite obvious to me that there is a very complex interaction between genetics and environment. Some populations benefit from breast feeding, other populations do not. This is genetic. There are clearly some hereditary differences which have a measurable consequence in brain development. To what extent do these explain that one random person might be an idiot, while another might be a genius? I honestly don't know, but we shouldn't shut down debate.
Yes, I am serious, and I am not disagreeing with your point, which as I wrote about in a comment bellow was clarified in your first response to me in this thread, I actually do agree about your last three paragraphs.
It appears however that you stopped reading my comment when you saw this the second quote that you wrote, here what I wrote before:
"What I see sometimes in these discussions is people throwing the "hot potato" in the hands of their detractors, people that believe in the difference between groups throw the potato in the hands of the disbelievers and accuse them of being obtuse for trying not to advance an "obvious truth"."
This type of accusation is fairly serious in academia it's akin to say that you just invented data to fit an experiment, mind that I do not have a side in all this, I'm interested in this as a statistician, my point was to get you to give some names of the people that "have become crusaders, trying to squash any debate or research into this topic, making it taboo." No one was given and I said that say this about a group of people and not give any name is unfair.
Everyone knows about who get accused of being racist, Linda Gottfredson for example who received grants from the Pioneer Fund, I do not know about others that received grants from this Fund but I can say about Gottfredson, she came to Brazil two years ago and talked to an audience of students in Brazil, some of whom have visible African ancestry and I can attest she's not racist, she does not differentiate people because of their ancestry and do not act different answering questions of asian-brazilians, people with jewish surnames or afro-brazilians, she's honest her research and that's all.
Mind also that I have spent some time in academia and the majority of people I saw really hates politicized research, there's exceptions of course, some social scientists, historians, some legal scholars and economists, but I did not count psychologists in this group. As I said to you I asked some psychologists to provide papers some of them fairly recent.
This was my last comment in this thread it was a good discussion.
Refusal to allow investigation? According to these papers, their has been very extensive investigation with a largely null conclusion. However people continue to push the idea that intelligence is genetic.
A null result doesn't prove that intelligence is not genetic, it only says that whatever genetic components there may be have not yet been disentangled from other genetic and environmental influences.
Consider the sorts of policies someone who wanted to maximise productivity in society would develop if it was found that genetics was a greater influencing factor...
Though I do realize that some people think this way, it strikes me as wholly bizarre. If you can identify a strong genetic component of intelligence, the obvious conclusion to me is to develop genetic therapies to boost the intelligence of the entire population, with the greatest gains to be had among those who would otherwise be on the lower end of the scale.
> There is no physiological model for human intelligence...
No? I've read several. For example:
"The pronounced convolution of the human cortex may be a morphological substrate that supports some of our species’ most distinctive cognitive abilities. Therefore, individual intelligence within humans might be modulated by the degree of folding in certain cortical regions. We applied advanced methods to analyze cortical convolution at high spatial resolution and correlated those measurements with intelligence quotients. Within a large sample of healthy adult subjects (n = 65), we detected the most prominent correlations in the left medial hemisphere. More specifically, intelligence scores were positively associated with the degree of folding in the temporo-occipital lobe, particularly in the outermost section of the posterior cingulate gyrus (retrosplenial areas). Thus, this region might be an important contributor toward individual intelligence, either via modulating pathways to (pre)frontal regions or by serving as a location for the convergence of information."
When we examined the same regression model excluding ICV, some cortical measurements were associated with IQ frequently in frontal and temporal lobe. It might conclude that human intelligence is significantly correlated with the cortical complexity coming from brain size, rather than cortical shape itself. The combination of various cortical measurements explained 52.57% of IQ. The results showed that they were more useful for prediction of human intelligence than alone.
I'm not defending these particular papers. I'm just baffled at the comment that there are "no" physiological models for intelligence.
The following paper appears to directly contradict your assertion that "there does not exist any inheritable, physiological difference that would influence intelligence":
"Variation in gray matter (GM) and white matter (WM) volume of the adult human brain is primarily genetically determined. Moreover, total brain volume is positively correlated with general intelligence, and both share a common genetic origin. However, although genetic effects on morphology of specific GM areas in the brain have been studied, the heritability of focal WM is unknown. Similarly, it is unresolved whether there is a common genetic origin of focal GM and WM structures with intelligence. We explored the genetic influence on focal GM and WM densities in magnetic resonance brain images of 54 monozygotic and 58 dizygotic twin pairs and 34 of their siblings. ... These findings point to a neural network that shares a common genetic origin with human intelligence."
I'll concede this point - there exists evidence that some physiological traits may correlate with intelligence. But there does not exist a model of why or how those traits influence intelligence.
There does not exist much variation across 'societies' of animals within the same species - one tribe of baboons is much like another tribe - but there exist vast gaps between societies of human beings, so far as these gaps influence the environment of individuals among populations, and entire populations as a whole.
There is no physiological model for human intelligence, and since only physiological traits are inheritable (though psychological traits may be derived from morphological differences) there is no model for genetic influence on intelligence. Since there is no model, you can only blindly test a black-box hypothesis - and the results from those tests appear to support the conclusion that there does not exist any inheritable, physiological difference that would influence intelligence, controlling for societal factors.