Intelligence: Nature vs Nurture

Thanks for the clarification. Your position is clear to me now. What I'll discuss here in R2 is the fact that your position, And the studies you have linked, Are flawed. The MISTRA study is flawed enough to be flat out called bad science. The Texas Adoption Project's findings are more valid, But also critically flawed in several ways. Your opinion on this matter is colored by flawed science. More recent and better conducted studies have found far less statistical 'heritability, ' (Adoption results for self-reported personality: evidence for nonadditive genetic effects? Plomin R. Et al) (The heritability fallacy David S. Moore et al) although after hours of reading through studies, Criticisms, Et cetera I have found this notion to be meaningless when it is attributed to human intelligence. Lastly, I will conclude that an alternative way of understanding nature vs nature is necessary to make the calculation of which is, On average, More influential. 1. MISTRA This study is incredibly flawed. I've read a 30, 000 word document on the matter. (Twenty Two Invalidating Aspects of the MISTRA by Jay Joseph) I'll summarize a few points. 1a. The initial control group for this study was ignored in its conclusion. The data from that control group was not published. It still hasn't been fully to this day. Decades later. MZA twins (100% shared genes) were studied. DZA (50% shared) were the control group. A statistical significance needed to have been drawn between the two groups. 1b. When a partial sample of the DZA group was released, It showed no statistical significance to the conclusion of the study. 1c. By failing to analyze with the control group, The study ignored 2 critical steps of its own group's procedure when coming to its conclusion. 1d. The full research data, Even outside the DZA group was never made public for researchers to view themselves. 1e. The twins from the study were not all raised apart. Many of them knew and had interacted with each other. The method of finding these individuals can hardly be called unbiased. 1f. They assumed that similar environments played no part in developing similar traits. This leads to an immediate bias on the side of genetics. 1g. I could go on all day, But the leader of the study, Bouchard himself, Said that many aspects of it would not hold. 2. TAP 2a. Sample Size of 181. 2b. Most of the children were born and adopted by white middle class people who were slightly above average intelligence. Most of the people who responded to the follow-up study tended to be the most intelligent among this group (Differential Inheritance of Mental Abilities in the Texas Adoption Project, Texas@Austin study) 2c. The aforementioned Differential study I mentioned found 3 subscales with genetic contributions, 2 with environmental, And 1 with neither analyzing the same data. The researchers note that some amount of intelligence can be shown to be genetically inherited, But they don't try to pin a number on this. More interesting is that they find the intelligence of children reared apart from their biological parents has a higher correlation than the intelligence of parent and child not separated. This leads to some interesting speculations. However, They note that all of this should be taken with a grain of salt until further replication has been done. 3. Study Problems There are many problems with twin studies. Some geneticists have thrown much of them away. (The Trouble With Twin Studies, Jay Joseph) (The Twin Research Debate in American Criminology, Jay Joseph et al) 3a. They assume that twins create their own environment because of their genetics. This is circular reasoning. The MISTRA study you linked was the biggest example of this I've seen, Giving genetics a heavy bias. 3b. EEA (Equal Environment Assumption) is the assumption that both of the identical twins have roughly identical environments. This could not be further from the truth. This will be expanded in my next point, So here we go. 4. Nature vs. Nurture So we arrive at last. Your studies have not held to peer review or criticisms. They have not stood the test of time. They are, However, Apparently still cited often. Scientific studies though, Need to have results repeated over time in order to be deemed factual. The methods by which they analyze their data need to undergo scrutiny. If you make assumptions, Which any 'heritability' study on human intelligence inevitably does, You come back with incorrect, Or at least biased results. Your studies, And you, Are assuming that people make their own environments based on their genetics. That similarities in environment means similarities in genetics. This is an extremely controversial assumption. Your studies, Even if they were done in good faith, Would still not lead to conclusions that could be generalized. Minnesota Statistics (from Minnesota State Demographic Center) show that 81% of the state is white in the current year. They show that minorities have been growing. When MISTRA was initially done this percentage was 95%. The income divides in Minnesota aren't that large. How is this a cross sectional study? The idea is to eliminate as many environmental factors as possible, However no two environments are the same. There is no way to scientifically accurately determine what percentage of intelligence is inherited because of this. Genetics research is largely ongoing. They can't point to specific genes that would make people do any of what they assume it does. It operates on a hunch, For now. There's a reason nature vs nurture is still a debate in science. Reasonable individuals do not take 2 studies in the late 1900s one of which has shady practices at best the other doesn't show a terribly interesting genetic link and even if it did, Not one that could be generalized and then say that this is foolproof evidence that genetics determine intelligence (or in your case you believe IQ is intelligence). 5. How to analyze If heritability is a hotly contested subject among scientists, How should we analyze which is, On average, More important? Nature gives us our raw processing power. Nurture is what information we are given to play with. Is a computer more intelligent if it is given great processing power, But no information to process? Is information useful if it is unable to be processed? No. What my opponent is doing is giving everyone the same nurture by saying "on average" and then saying nature is more impactful. I can simply say that 'on average' everyone would have identical natures as well and this debate is irrelevant. However, If everyone's nurture, On average, Was 80% on a scale of how good it could be to how bad it could be, And everyone's nature on average is 80% as well, Nurture would still win when we analyzed based on moving the sliders in any direction. Your nature could give you the processing power of a genius or the processing power of the most crippled low functioning downs syndrome person on the planet. Your nurture, If moved. Up or down, Could either make you a cave man trying to learn his own habitat versus the most informed and potentially influential scientist in the world. If everyone is currently receiving a decent nurture, Then genetics are more impactful. However, Does that mean that nurture gets no credit? My opponent is attempting to make all nurtures equivalent with term 'on average. ' While allowing genetics to change from person to person. This is, In my opinion, A silly way to view things. So I will submit to the audience, Do you think people on average are more impacted by raw processing power or available information? Would you be vastly more impacted by the least amount of information possible, Or having your processing power diminished to that of a downs syndrome person? I for one, Think I would fare much worse as a super-genius cave man than a mildly retarded man with a cell phone in this day and age. May your thoughts be clear, -Thoht