Tribalypredisposed: I've edited your post above to fix your quote tags, I hope you don't mind. The formatting you had was just confusing to read through.
tribalypredisposed wrote:Tribalypredisposed response: A few issues to cover. First, about your "shrew" remark. The assumption larger brain = more intelligent is not about relative size but overall size, generally, although the assumption magically vanishes when considering elephants and whales. You can find various remarks in the literature, for example, about how the "hobbits" have upset some common assumptions as they had chimp sized brains and still had some sophisticated tool use and manufacturing evident.
No, that's certainly untrue then. Talking about relative brain size is incorrect, but it's more correct than absolute brain size. No scientist with a first year education in psychology or neuroscience would suggest that
absolute brain size is an indicator of intelligence.
That's why they came up with the encephalisation quotient, as bigger organisms require bigger brains just to perform basic functions.
tribalypredisposed wrote:I have tried to find some sources for Entine's claims, and have not found them. He seems to have a book out in 2008 but none of the articles I have found mention what his sources are for the various claims he makes. I have found an article stating he claimed further recently that "among those in the “genius” category — people with IQs of 130 or higher — Jews outnumber members of other ethnic groups 45 to one" -http://njjewishnews.com/article/middlesex/author-asserts-genetic-roots-of-jews-peculiar-genius
Unfortunately, without a source we don't know what conclusions we should draw from those conclusions. We don't know whether the methodology is sound, or which IQ test they were using, etc.
tribalypredisposed wrote:Avoiding Murray for obvious reasons, this source seems likely to be credible but I have no access to the whole paper. -http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6W4M-4JYTRWC-2&_user=10&_coverDate=12%2F31%2F2006&_rdoc=1&_fmt=high&_orig=search&_origin=search&_sort=d&_docanchor=&view=c&_searchStrId=1626301092&_rerunOrigin=scholar.google&_acct=C000050221&_version=1&_urlVersion=0&_userid=10&md5=61dce6bf684a93b3734e64a5b56e67e6&searchtype=a
"it is proposed that the best reading of the IQ of Jews in Britain is 110. It is proposed that the best reading of the IQ of Jews in the United States is 109.5."
Hmm.. well even before we dissect the claims made here, we need to look at some other factors that might affect the validity of the claims: firstly, the paper is by Richard Lynn who is well known for misrepresenting results, data mining, biasing results, etc, secondly, the paper was published in a journal that has a pretty low impact factor, and thirdly, Lynn is on the editorial board of that journal, which calls into question whether it received adequate peer review.
But assuming that it's a valid paper, the main problem is that for some reason he's using data from 1946 and 1958, where he's calculated the IQ scores himself without stating how he's done this or what IQ system he's using.. Lynn is also known for inflating his scores by adding on his own weightings for the Flynn Effect, with the assumption that this is equal across all groups, countries, ages, etc, when this simply isn't true.
Effectively, given the problems with his methodology, it's surprising that he could only blow out the scores to 110. It's a poor study though.
tribalypredisposed wrote:As to the culture issue; I could accept small variations in achievement based on culture amongst those living in the same society with the same educational institutions, but I think we would have to have very compelling evidence indeed to claim that a 15-1 overrepresentation could be purely cultural. That is a huge dominance of one culture over another. There are no peer reviewed sources I am aware of that claim anything more than a 50% contribution for nurture in IQ or intelligence. Which would not account for the differences we see.
I don't understand why you're surprised about the effect of cultural influences. The American Psychological Association's review of the literature on the genetic and environmental factors found that the effects on genetics on intelligence varies throughout the lifetime of a person - through most of our childhood and teenage years, genetics only accounts for about 20% of our intelligence, whereas near the end of our life it accounts for around 80%. Overall, across our lifetimes there is a near equal split between nature and nurture.
tribalypredisposed wrote:You mention sexual selection for greater intelligence. I know that professor Geoffrey Miller, at U of New Mexico I think, has made this claim, as well as Dorion Sagan and John Skoyles in their book "Up From Dragons." It is not a viable hypothesis. Intelligence is not an "honest signal" of fitness. One might assert that larger brains were selected for, but you yourself argue here in several posts that no such connection exists. So demonstrating greater intelligence is not at all straightforward.
I'm not sure why you think the theory is disproved. I don't personally subscribe to it, but it still appears to be popular in the literature. You don't need external signals like brain size for intelligence to be selected for, females could simply pick whichever male brings the most food back and, on average, the male who brings the most food back is the smartest, and so on.
tribalypredisposed wrote:Further, if intelligence is related to brain size, then the gender doing the sexual selection is also paying a large fitness cost for their preference in the form of death during childbirth. If there was no real fitness advantage to greater intelligence then those women who picked men with larger brains in sexual selection would have been selected out of the population. Finally, the human brain is not simply a chimp brain grown three times as large. Various parts are significantly larger than three times the size they are in chimps, for one thing. There would seem to be very few ways that women might know the relative sizes of the prefrontal lobes of their potential mates.
I'm not sure why you keep repeating this. Even if we assume that there is no advantage to intelligence (which I don't understand why you want to do this? No evolutionary advantage does not equal no advantage), and that an increase in intelligence leads to greater rates of death during child birth, this doesn't mean that the trait will be removed from the population.
This is basic evolutionary theory: sometimes deleterious genes spread throughout the population, and sometimes advantageous genes get removed. Natural selection is a rule of thumb, not an absolute rule.
tribalypredisposed wrote:As for the "fire" hypothesis, one still needs a reason why intelligence evolves. It is not enough to suggest what may have allowed it to be possible.
The point of the fire example is that intelligence doesn't evolve - the base rate of genetic intelligence could have stayed the same, whilst the access to nutrition increased intelligence.
tribalypredisposed wrote:It is really odd to me that so many have difficulty accepting the most straighforward explanation; that intelligence was adaptive and increased fitness, and therefore was selected for by evolution.
Nobody is arguing against the idea that it could have evolved, there is just no reason to currently think that it has evolved since the evidence is weak at the moment - and the evidence for difference between populations of humans is nonexistent.
tribalypredisposed wrote:Fire certainly changed our relative fitness as predators and prey and opened up many new food resources to us, but humans were still subject to the whims of nature and her droughts and so on. Food scarcity would then limit calories available....unless the smarter individual managed to get more calories then the individual with a smaller brain, the smaller brain would have the advantage. But again, it is not just about calories. Larger brains often kill women giving birth, larger brains mean far longer periods of dependance on adults and longer vulnerability to predators. These are large fitness costs, and fire or sexual selection both fail catastrophically to have any answers for these costs. The only viable answer is real evolutionary selection of the more intelligent and therefore more fit.
But the "fittest" organisms, on paper, don't always survive.