One of the calling signs of the inheritability of intelligence is that fossil records demonstrate our ancestors systematically acquiring larger and larger brain mass over the course of hundreds of thousands of years. This can only be the result of evolution favoring those with bigger brains, or pre-historic chicks diggin’ da humpin’ those with bigger brains. Either way, the steady, aggrandizement of brain mass is indicative that Homo Sapien’s basic wiring has undergone radical alterations in design what is, in evolutionary terms, a heartbeat. The main problem with the debate of environment vs. genetics, as I see it, is that there isn’t yet a sufficient understanding of the mechanics of intelligence to provide the framework for a meaningful opinion. It’s like monkeys debating the merits of hardware vs. software on the Space Shuttle – any correct opinions are probably as much the result of random chance as they are brilliant deductions. I’m not yet convinced that we’ve developed a firm model of the mechanics of heritability. It’s assumed (without much in the way of proof) that identical twins must have been subjected to identical genetic influences. But if our DNA constructs us in a similar fashion to the way the Soviet Union constructed MIG fighters (ie, only to a certain technical specification except on drunken Tuesdays), then it’s pretty much a slam-dunk that no two people in history have ever been subjected to exactly the same genetic construction. Just as one twin often is better looking than another, it might be the case that a some of the difference in intelligence was randomly assigned by genetics within the construction tolerances of this or that neurological substrate. With regards to environment I’m even less impressed - many of the measurable differences between identical twins occur, upon analysis, for no apparent reason whatever. What appears to be an environmental influence can actually be one of a number of things: 1) A genetic influence exerted by non-inherited DNA. For instance, perhaps a slight degradation of eventual intelligence in one twin was on account of the unknown and unanticipated impact of a viral DNA. 2) A feedback system whereby certain genetic traits are being triggered by certain environmental triggers. (ie, what appears to be purely environmental is actually a complex interaction between inheritance and environment, such that any two sets of twins might react, but differently, to the same environmental stimulus).
For those who doubt the heritability of IQ... how do you explain the extremely high correlations of IQs of identical twins who are reared separately? Why are their scores nearly identical?
Glaucon said the wikipedia article has the facts right. But the Wikipedia article says that IQ is heritable, which is the exact opposite of what he said is his opinion. So if you're a person who thinks IQ is not inherited and the Wikipedia article acknowledges that it is inherited, why would you say that the article has the basic facts correct, like he did?
If intelligence has no strongly inherited characteristics, then what is to explain the systematic accumulation of brain mass in our ancestors over the course of hundreds of thousands / millions of years? Fossil records makes it a certainty that larger brains were being favored. Otherwise, there would have been no net increase in size.
LOL take one of the twins and put her in a Somalian prison, then take the other and put her in richville connecticut, leave them both where they are for 10 years. I guarantee you I.Q's will be flying everywhere. Okay forget about that experiment. Put a child of a nobel laurent in a Taiwanese black market as a horder for 10 years, I guarantee you the I.Q will drop so hard that there will be another Earthquake. People that think intelligence is hereditary are fucking stupid.
Genes are nothing but empty pages of books, and as in all books someone has to put something in them from somewhere.
Children are resilient, but even so, there is a limit to that resilience. If a child is starving and is experiencing PEM, is that going to have an impact on his or her IQ as an adult? Probably. However, the point is, that's not normally the case in first world countries. Indeed the heritability of IQ is higher in first world countries. Do you know that for a fact? Of course not. I really don't know what to say about this, except read a book. Read some science. Here's a good start. http://en.wikipedia.org/wiki/IQ By the way, you never answered the question about why identical twins score so similarly on IQ tests, even when they are reared separately. Also read this article from New Scientist. Let me know what you think about it. http://www.newscientist.com/article.ns?id=dn1520
Really? I'm easily twice as smart as my dad who's easily 3 or 4 times as smart as my mom, are you telling me that's genetic? My dad was the first person(that I know of) in his family to graduate high school, nobody in my mom's family(as far as I can go back) has done so. I just turned 16, and I'm 9 months away from graduating. To this point, since I've started my schooling online, each of my course averages have been 94% +, in advanced clases. So you're telling me that it couldn't be the fact that I had a good teacher when I was young, and the only logical exclaimation is that I'm illegit? I don't think that's what he was saying.
Each generation generally does better than the previous one for many socio-economic reasons. And you are not 3 or 4 times as smart as your mom. She would have to have an IQ of 30-40 for that to be true, and I am assuming that you are near-genius level just to be conservative with my estimate. This is why IQ tests simple spatial skills and pattern recognition, rather than quizzing you on history. It is a general test of intelligence regardless of educational background. As a matter of fact, I'm surprised that you are so smart and yet don't know any of this. Not to be rude, but I was very young when I learned about the history of the military and the IQ tests. Hmm...
Please explain in more detail how the breeder "removed these traits." Traits are inherited. He would've had to look at the original sire and dam, determine where the unwanted traits came from, and then stop any future breeding of the source. Either the sire or the dam were replaced.
Every trait of every species on Earth has developed by way of evolution, which is by definition the alteration of a species genetic characteristics in response to various pressures. It is known that Homo Sapien's brain structure has been altered radically within a short timeframe (less than a million years). My question is, if the brain isn't an expression of heritability, then how were these changes carried out? Also, I'd be facinated to know what it is about black market specialists that some here think makes them dumbies? Met some back-ally types in China in 2003. Didn't strike me at all as stupid.
You are perfectly right, but that is not the question here; the question is if IQ is inherited. 1. intelligence does not equal IQ. 2. a trend in inheritance of intelligence over a single generation is not the same as a trend of increased intelligence over a prolonged period of time in the entire population. In fact two extremely smart people can in theory and practice easily produce a really unintelligent child.
IQ, from my experience, seems to be a rather accurate predictor of the ease at which one can assimilate new information and apply it to solve problems (mathematics, chemistry, physics, etc.) For example, I have been diagnosed with a high IQ and, sure enough, in school I take the most advanced mathematics and science courses and they still prove to not be much of a challenge. I frequently help the other students understand more difficult problems. Now, on inheritability, I think that it's inheritable to some degree. However, I think that due to the complexity of the human genome, there can be countless other factors in one's genetic coding that can influence intelligence, like mutations. If IQ was completely inheritable, then we would not have child prodigies with stratospheric IQs born from parents of significantly less intelligence, right?
I've posted some IQ research at http://www.sciforums.com/showthread.php?t=60779 Research in support of the high heritability argument.
It depends on what you mean by inherited, inherited form a parent or inherited from a previous lifetime, or inherited from the local environment?
All this might be true but you are missing the larger overview. I.Q might be inherent but the final say always has to do with the human socio-enviroment. How much inheretance, type of inheretance, and the harness of the inherent I.Q still beckons on the enviroment. Lets take a Doctor's son, he may grow up to eventually become a talented musician or a restuarant owner, or he may even grow up to become a great astrophysists, and as influencial as the socio enviroment is he may also grow up to become a dish washer. You have to look at the larger picture to get my reasonng. Inheretance provides that all things have to be ideal for it to work, but we know that an Ideal universe is a very strange universe indeed, strange because it does not exist. First world countries can become bankrupt, specialist jobs can decline in demand, economic conditions can take their strains on a family. -Every feature of the Human body is a function of years of evolution;the eye, ear, toes, tongue, and even the cognitive system. And evolution is a properly synchronized dance with the enviroment. The human genetics did not become different from the frogs because we choose to, but because the enviroment choose it that way. You see, its not that genes are not passed down, but the content and variability is determined by external factors. The enviroment always has the final say, and the enviroment matters more than the genes, which is why we scientists give way to the enviroment in this discussion. After all what good is the human body in outer space when it cannot survice without oxygen? - A woman with perfect genes can give birth to a deformed child if she drinks alchohol during gestation. Again, alchohol is the external factor. - Identical twins may score identical results, but my guess is that very often identical twins live very similar lives. I am not far from the truth. Nonetheless, many twins also score very differently in I.Q tests for a fact. - Genes are nothing but books that were filled wth information millions of years ago, and we know that certain genes also mutate, which is a direct influence of enviromental conditions. Anybody can grow up to be what they want to be but they need two things; interest and discipline. You can't do anything intelligently without these two human conditions, and there is no known pre-programmed gene for this. Even if you are a tall black man, it doesn't mean you are automatically a basketball player, not without training and interest. In conclusion, I'd like to quote Aristotle, "Nothing comes from nothing", not without input and effort. Genes may work but the enviroment overides genes,which is why we give yield to the enviroment.
IQ and the Wealth of Nations. is a brilliantly-conceived, superbly-written, path-breaking book that does for the global study of economic prosperity what The Bell Curve did for the USA. Richard Lynn and Tatu Vanhanen examine IQ scores and economic indicators in 185 countries. They document that national differences in wealth are explained most importantly by the intelligence levels of the populations. They calculate that mean national IQ correlates powerfully—more than 0.7—with per capita Gross Domestic Product (GDP). National IQs predict both long-term and short term economic growth rates. Second in importance is whether the countries have market or socialist economies. Only third is the widely-credited factor of natural resources, like oil. One arresting fact emerges: the average national IQ of the world is only 90. Fewer than one in five countries have IQs equal or near the British average of 100. Almost half have IQs of 90 or less. This poses a serious problem if the book’s conclusion that IQ = 90 forms the threshold for a technological economy is correct. [ . . . ] Complete text at http://www.vdare.com/misc/rushton_iq.htm
Chatha, you still didn't explain why identical twins have nearly identical IQs. You said the reason their IQs are so similar is because they often have the same lives--or because they have the same upbringing. This doesn't explain anything. Siblings who aren't identical twins IQs correlate, but the correlation isn't anything compared to those of identical twins. Not only that, but the correlation of IQs of identical twins who are reared separately are still extremely high. You didn't explain anything. At this point, the best thing you can do is some reading. No offense or anything, but it doesn't seem like you know a whole lot about this.
The phenotype is a combination of the genotype and environmental influences. Let's get that straight right now. Yes, all of our traits have developed via way of evolution. We are born with a certain aptitude of intelligence. Whether or not we fulfill that aptitude depends on our environment: when, where, and how we are brought up, and what we learn, how we are conditioned and how we are raised.
