Nature vs. Nurture: "Rationality"

Pro Case:C1:Con claims that the decline in education is irrelevant because it's only a relative decline. This simply can't be true. The way we value education is precisely how it is doing as compared to other educational systems, past or present. For example, we know we're worse off now because we were better off before. And, we know we're not doing that well now because most advanced nations are doing better. Obviously, some schools will be better than others within the country, but even the overall state of education in the U.S. has been relatively outmatched by the overall states of other nations. There are certain countries with much more intensive school programs that do better than the U.S. on tests of IQ.I used "stimulating" as an oversimplification for describing the addictive nature of media-based technology and the adverse, drug-like effects it is being demonstrated to have on the human brain and mind in a growing body of research. This, for one thing, cannot be cast aside as impact-less or unimportant, as the effects are quite significant (they're physical and behavioral), and the scope of those affected is only going to grow. Second, it is a perfect example of a "shared" environment that is also a "unique" environment, as the Internet, cell-phone networks, and even cable television are a sort of shared environment, whereas the interaction of each individual with their devices and programs is a unique environment. So clearly, both "shared" and "unique" environments (put together they might simply be called "experience") still have substantial effects on IQ.C2:Con is right that both being self-directed toward education and parent-directed toward education are important environmental (i.e. experiential) factors in affecting IQ. However, that was my argument. It is much more likely that a person with a slight, inherited advantage in IQ will be both self-motivated and parent-motivated to do well in school, thus reinforcing their advantage. Conversely, someone with a slight, inherited disadvantage in IQ will be less motivated to do well in school academically, and their parents might encourage success in sports or some other activity. This can explain why twins correlate on their IQs even when separated.It's obviously difficult, if not impossible, to describe the relative impact on IQ and conscientiousness from meditation and exercise at this time. The studies didn't measure IQ in any of them, let alone study their genes. They look more at behavior, brain structure, and health. Suffice to say that these types of behaviors may or may not change your genetic potential, but they certainly help you express it maximally.As for the large IQ changes associated with brain changes, Pro presents no evidence to support his claim that these can't last. And as for the improved fluid IQ, some studies have "debunked" it while others have replicated it. I would say the jury is still out.C3:Con's alternate explanation for the abecedarians is plausible, but how likely is it considering that the improved group was taken randomly out of another group of low-income children, and that the remainder of that group served as the controls and did much worse on these measures of lifelong achievement? The group that did 4 times better in graduation just happened to have higher IQs in the first place, is what Con appears to be arguing. Con has no evidence of this, so I think the better explanation is that intervention did help.As for the Norwegians, even if the improvement did fade, hat would suggest an even larger improvement than the measurement, which was a significant improvement of 4 IQ point per extra year of education. It's unlikely that IQ accelerates at that rate naturally when rising to its peak at 26. The problem with twin/adoption studies shows itself here as well. Regardless of which shared environment you're in, your genetic tendencies usually tend to be reinforced by appropriate unique environments, whether its due to motivation from others or yourself.C4:Con's response is simply not what the research concluded. It concluded that the genetic variance of one's own IQ was 24% across the whole lifetime, or a very large portion of it (11-79.) So the fact that IQs are somewhat similar, but also somewhat different, at the end of that period doesn't lend itself more to either case, but Deary's conclusion about the genetic variance does.Con Case:R1:Deary is very careful in his approach and I wouldn't think that he would put forward such numbers unless he had taken measures to work Con's concerns into his conclusions. This is probably why he somewhat widely described the genetic variance of IQ between individuals as between 40-50%. My criticism of twin studies isn't concerned about the method0logy per se, even though it doesn't actually take information about specific genes into account, but about the misled conclusions it's responsible for in the public mind. Saying correlation is not equal to causation is important, because if all you do is cite .70 or .80 correlation for twins, it leads people to thinking that IQ is 70% or 80% genetic, when the more detailed research (Deary) shows that this is probably a large overestimation. The main problem is that IQ, like education earlier, is a trait valued on a relative basis. What makes the IQ of a genius special, or a mentally-disabled person unfortunate, is the difference between it and the average. These differences are what we call variance, and Deary's research has made the best scientific attempt so far at estimating the causes of these differences. His best hypotheses so far are that the variance between individuals is 40-50% genetic, meaning 50-60% is experiential (all of the controversial types of 'environments" combined), while the variance within an individual lifetime is only 24% genetic, meaning 76% is environmental (i.e. experiential.) Thus, the problem with trying to analyze IQ in terms of similarities is that it's a relative trait whose differences are more important, and since these differences are mostly caused by external, as opposed to inherited, factors then the "environment" affects it more than genes.R2:Con here says the differences in conscientiousness are caused mostly by whatever is not genes or shared environment, which is generally described as "unique" environment, but what I would call individual experience. And I would argue that this is, as for intelligence, the determining factor in most of the differences.R3:I apologize to my opponent if we've had a bit of a misunderstanding, but my interpretation of "nurture" and "environment" is essentially everything that is not genes. i.e. experience. This is what I am and have been trying to prove is more important than inheritance in 'determining' IQ. I'm sorry if he judged me as having a similar outlook on these words as most people, and if I have not been clear enough. However, this is clearly what Deary means when he says that the rest of the variance between IQ that he has not accounted for with genetics is probably due to "environmental influences." Therefore his evidence, along with the growing neuroscientific research into brain changes associated with behavioral and performance changes associated with all sorts of specific activities, and the obvious benefits of optimizing certain kinds of shared environmental influences, is sufficient to demonstrate that in the case of rationality, nurture edges out nature and beats it.