Re: VS: [evol-psych] Scotland lags Europe in IQ league
- Irwin Silverman: This is not to say that selection for IQ did not occur, but it does suggest that it was not linear positive directional selection but selection for levels closer to the mean.Jay R. Feierman: There is a difference between intelligence, IQ and IQ test scores. A number of writers on this thread used these terms interchangeably. They mean very different things. I'm certain that there has never been direct natural selection for "IQ." That being said, if IQ test scores predict academic and economic success in the industrialized modern world, where is the evidence that the brain structures whose functions are measured by IQ tests were ever selected in the EEA? The only evidence of which I am aware is that currently individuals with higher IQ test scores have less, rather than more, reproductive success, at least in the modern industrialized world. Saying that natural selection was selecting for average, rather than high IQ test score individuals is retrofitting natural selection to accommodate the finding that most people have average IQ test scores and only few people have very high or very low IQ test scores. That can result from a variety of other mechanisms and artifacts, other than natural selection "pulling on the mean." If IQ test scores are positively correlated with brain size, the differences between the head circumferences of high, average and low IQ test score individuals (excluding brain damaged very low, moronic and idiot IQ test score indidividuals) is insignificant (a few percent) in terms of the ability of the human female pelvis to allow the head to pass through it during parturition. Large heads theoretically could be a constraint on achieving higher IQ test scores if the larger heads can not pass through the pelvic inlet. However, if having babies with bigger and bigger heads (and hence higher and higher IQ test scores) would increase a woman's inclusive fitness, it would not have been very difficult through natural selection to increase the size of the human female pelvic inlet by another 25% or so. Already, there is much variation in the modern human female pelvic size, which suggest that there is not much directional selection pressure for the largest of pelvises. Unless one can demonstrate a contraint (such as big heads can't fit throught the pelvic inlet) on more of a trait, such as head size, average is the result but not the object of natural selection.
- Jay R. Feierman: Actually, the few [high] IQ score people in a social group help the group by helping the group to have a lower death rate, rather than a higher fertility rate.RKS: Lowering the rate of death in early infancy has had a profound impact in recent times.Jay R. Feierman: True. Once an individual is born and they die, that's counted as death rate, even if they are just a few days old. To be counted as birth rate, one only needs to be born. The demographic transition is mainly due to lower infant death rates.RKS: Saying that the islanders could [not] fix the generators is too brief a comment. Could you fix the generator or phone system?? No?? But you're a white boy from the USA? We must not think in terms of what unqualified people are capable of - there is not much of a difference between the islanders and suburban USA.Jay R. Feierman: No, I couldn't. I wasn't implying that the natives were any less intelligent than the individuals who invented the generators or the phone system but just that the society in which the natives live did not have the technological capability of maintaining such systems because of lack of electricity, manufacturing capability, supply lines, roads, technical training, etc. My point was that even in the global economy the third and fourth world societies can't just automatically incorporate the technology of the industrialized societies, as they can't maintain the equipment, etc. As a result, much technology can not be transferred to the third world. I've been in medical clinics in east Africa that didn't have electricity or running water, so the medical care that could be delivered at the clinic was very primitive.