Ch. 7: Heredity or Environment?

(p. 53)

There are many studies of twins, including a comprehensive study at the University of Minnesota by Dr. Thomas J. Bouchard Jr. that received worldwide attention The study showed that the IQs of identical twins raised apart were much closer than random adopted children, and that they were even closer than for fraternal twins who were raised in the same home, and who attended the same schools. Not a single twin study has ever contradicted these results.

Let me emphasize this important point --identical twins growing up in completely different environments --with different parents, different schools, different diets, different political and religious persuasions --have IQs closer together than those of fraternal twins raised in the same family. If intelligence is primarily created by environmental factors, certainly the fraternal twins raised together in the same familial, social, and educational environment should obviously have much closer IQs than twins who were raised apart.

I looked up and read more studies demonstrating the power of heredity in intelligence and found that even those focusing on identical and fraternal twins raised together yielded additional strong evidence. Because fraternal and identical twins are born only minutes apart and usually grow up in the same environment, they provide a way to measure the impact of heredity, while environmental factors are held steady.

Identical twins' IQs are much more strongly correlated than are those of fraternal twins. Correlations generally run about .85 for identical twins raised together as compared to .60 for fraternal twins. Psychologists Bouchard and McGue reviewed over 100 studies comprising 40,000 kinship pairs, almost all of that type of cognitive study reported in the scientific literature.

In all the studies comparing identical and fraternal twins -- it is found that separated identical twins raised apart scored closer in IQ than fraternal twins raised together! Other sources of excellent data are found in studies of adopted children. Adopted children are closer to their genetic parents' IQs rather than with their foster parents who they grow up with.

The scientific research on intelligence has silenced all but the most belligerent egalitarians. Unfortunately the mass media in America are still promoting the unscientific and discredited environmentalist views of fringe neo-Marxist and far-left elements such as R. C. Lewontin, Steven Rose, Stephen Jay Gould, and Leon Kamin. The media almost always fail to mention these men's political affiliations, such as Kamin's former position as New England editor of the U.S. Communist Party's weekly newspaper. Similarly ignored is Lewontin's pivotal role in the pro-Marxist, Vietnam era "Science for the People," and Gould's smug recounting of learning his Marxism on his father's knee. Much of the public is still largely unaware of the overwhelming scientific evidence showing the prominent role of genetics in determining human intelligence, but the scientific community has become aware of it. Snyderman and Rothman did extensive surveys of those scientists involved in psychological research and found that by the middle of the 1980s the vast majority believed that IQ was profoundly affected by heredity.

The Brain and Intelligence

Learning that IQ is primarily inherited made me ask the question, What precisely is inherited? Sophomoric as the answer seems; it is of course, the genes that construct the architecture and chemistry of the brain, along with all its overt and subtle variances. To accept the zero-heredity-impact argument of the Marxist Lamarckians, one is required to believe that, unlike any other human organ, the brain is not a product of the genes.

Scientists think that almost one-third of a human's genes are devoted to the brain, and those genes naturally vary. Intelligence is ultimately as physical as the structure that enables one to run with a football or shoot a basketball. It is rooted in the magnificent architecture and gray matter called the brain.

It is hard to imagine our minds as physically-rooted entities. After all, thoughts have no physicalness; we can't taste, touch, smell, see or hear them except in the confines of our own minds. Yet our brains are just as physical as the muscles in our arms and legs. Their construction and wiring is crucial to everything from our intelligence to our personality. Even our thoughts come from physical processes, both chemical and electrical, in our brains. The context of our mental abilities is dictated entirely by the structure, form, dimensions, density and chemical composition of the brain If the structure of the brain were not important then we could teach any dog to read Dostoyevsky or any orangutan to understand organic chemistry. The more primitive structure and limited size of their animal brains prevent them from having high intelligence.

Because Of the structure of some people's brains, not every human can be taught to read and write, much less understand the fundamentals of organic chemistry.

There are dramatic differences between the brain of the human and that of the dog, or for that matter, the orangutan -- that account for the differences in intellect between them. Even the dog and the orangutan have broad differences in their physical brains, and every zoologist would rate the orangutan as more intelligent than the dog. In fact, dog trainers report that there are sharp differences in intelligence between the different dog breeds, as well as distinctions in the breeds' temperaments and other aspects of personality.

When first faced with this information about intelligence in dogs, I wondered what difference between the breeds could account for the mental differences? Only one explanation seemed feasible to me: Different genetic heritages result in physically different brains.

Just because the human brain is larger and more complex than that of the dog or even the higher primates does not make it any less subject to the same laws of genetics. Each human brain is as unique as a fingerprint. In fact, brains are vastly more complex and diverse than fingerprints. Neuroanatomist Paul Glees, in his classic textbook The Human Brain states that the brain is the "signature of a genetically unique person." Most scientists agree that brains in higher primates and humans evolved larger over time because more voluminous and complex brains enabled problem-solving and learning skills. There is obviously a relation to the fact that a monkey has a large brain and is considered a more intelligent animal than a smaller-brained frog.

Even Charles Darwin cited numerous studies in support of his contention that "The belief that there exists in man some close relation between the size of the brain and the development of the intellectual faculties is supported by the comparison of the skulls of savage and civilized races, of ancient and modern people, and by the analogy of the whole vertebrate series."

What do the media gurus say about this? Years after I read my first article on brain size and intelligence, I read The Mismeasure of Man. Its author is an avowed Marxist, Stephen Jay Gould. He analyzed and tried to invalidate brain-size research data from the 19th century and therefore disputed the relationship between head size and intelligence. He ignored more recent --and more scientifically precise -- studies of human brains by researchers such as Todd, Vint, Simmons and Connolly. There have been numerous studies since Gould's book that show a strong correlation between brain size and intelligence.

With modern MRI (magnetic resonance imaging) capabilities, extremely accurate measurements of the brains of living human beings can now be made. In a groundbreaking experiment at the University of Texas, 40 students were divided into two groups -- one with IQs above 130 and another with IQs below 103. Since that time numerous similar studies have been done. A remarkably clear correlation of .35 was found between brain size and intelligence, a correlation actually higher than most traditional studies that compared head measurements and IQ. It became obvious to me that intelligence was primarily hereditary simply because it was determined by the specific characteristics of the human brain

Ego and IQ

The biggest obstacle in discussing the genetic nature of intelligence is our own egoism. Even though human beings universally blame outside forces for their failures, we consistently take credit for our successes. We don't want to think that we are limited in our horizons because of the inherent limitations of our genes, and we certainly don't want to give too much credit to our genes (something over which we have no control) for our achievements. We don't want to acknowledge that somebody else is truly smarter than we are. We can readily accept an athletic star's physical size and superiority but are reluctant to acknowledge mental superiority. Sure, many people can acknowledge an intellectual rival's educational level or experience, but most people are not as inclined to accept that a competitor has a superior mental ability. Yet hundreds of serious research studies continue to add to the evidence of genetic differences in intellectual ability. Indeed, general intelligence is one of the most highly heritable of all human traits.

As I read the studies of IQ and understood its great impact on our lives, I realized why the IQ issue was so important among racial egalitarians. Most people -- not just rural White "racists," but the leading egalitarians themselves -- readily equate human worth with high intelligence. If one brings up the argument that one race is more intelligent than another, the egalitarian instantly equates that position to be saying that the Black race is "inferior." It is odd that liberals who dismiss IQ tests as meaningless somehow equate low IQ with blanket inferiority.

How less assuming it is to see intelligence as part, albeit an important part, of the whole picture. IQ is only one of the characteristics that make up the human being, for a person can possess exceptional abilities and still not have an exceptional IQ. The way a person lives his life -- his responsibility, industriousness, honesty, courage, morality, and a thousand other qualities -- is also vital in evaluating his worth. To say that the Black race is inferior to the White race because the average IQ is lower among Blacks is much like saying that Whites are inferior to Blacks because the average Black is faster in the 100-yard dash.

Whatever their intelligence level, Black people were genetically well suited for their historical environment in Africa. To say that their inherited capacity to adapt to that environment rather than the environment of computers and aerospace engineering makes them " inferior" human beings is a totally subjective concept. They would be inferior to what we value, perhaps, but inferior to what they naturally value, no.

At the same time I came to understand all this, I also realized that Western civilization runs on a high IQ. It is the high-octane genetically-created fuel of our culture and of our technology. I concluded that if there is a significant difference between Black and White IQs, it will have a profound impact on our society. As I read more about IQ, I found out that the real political opposition to it erupted because of the racial implications. Now that I had a firm grasp of the relationship among intelligence, heredity and environment, I began to plow deeply into the subject of racial equality with a thirst for the truth.

As for myself, it has always been easy for me to accept my own mental inferiority in relation to many brilliant human beings. I have a respectable IQ, but when I read about and consider the special genius of men like Thomas Edison, Francis Galton, Isaac Newton and William Shockley, it is hard to be egotistical. Every human being is going to be inferior or superior at some endeavor. I am philosophical about it, for it doesn't diminish my own sense of self-worth to know that there are many men and women born smarter than I am or physically Stronger than I am.

Nor does it boost my self-worth to know that there are innumerable cretins on this planet. I decided at an early age to simply seek the truth, not only because it was valuable for its own sake, but also because I believed that in the unvarnished truth we can find solutions to the monumental problems facing this nation and the Earth.

All of this afforded me a useful starting point: Once I came to accept the power of genes and the validity of IQ as an important measure of mental stature, I felt that I was ready to take on the more emotionally charged question of whether or not there are significant differences in Black and White intelligence and behavior.

Thomas Jefferson's words inspired me as I delved into the most controversial subject in America. "There is not a truth existing which I fear, or would wish unknown to the whole world."