Genes R Us: Intelligence and prenatal genetic testing
Posted: Wednesday, May 2, 2012 5:00 pm
By: By Nancy Miller Latimer
At this time of year, many of us have children or grandchildren that will soon graduate from high school. Some of us are even blessed (and financially relieved) to have a “child” graduating from college. My oldest grandchild is graduating from high school and his mother is graduating from college this May. What a perfect time to visit the relationship between intelligence and genetics, the topic of my next two columns.
An undeniable trend in genomic medicine is the increase in prenatal genetic testing (PGT) to diagnosis severe genetic diseases and traits. Some of these disorders will absolutely guarantee a less than normal intelligence by any standard definition of intelligence.
Some babies, identified by PGT as genetically imperfect, will be aborted. Consider that more than 90 percent of confirmed Down’s syndrome pregnancies are electively terminated. Such is the gristle of genetic bioethics and an issue that is truly worthy of your sincere reflection.
If we could decide exactly what intelligence is, perhaps we could measure it accurately. I am by no means an expert in the definition or measurement of intelligence, but I have made a few observations over the last half a century plus.
When I am introduced to someone new in Union City, he or she may tell me that they (1) enjoy my articles, (2) they don’t always understand everything and (3) I am so intelligent. My responses are (1) thank you, (2) it takes time and frequent exposure to feel comfortable with new concepts and (3) I am not so very intelligent — just incredibly curious, respectively.
Although it is not politically correct to say that some people are born with higher mathematical inclinations, research at John Hopkins University seems to suggest otherwise (http://bit.ly/pESR9l) and that such aptitude manifests itself very early in the preschool years. But intelligence is hardly restricted to quantitative reasoning, like math.
Quantitative reasoning may be easier to measure, and more tied to technological advances, but it is no more important than qualitative components of intelligence, such as one’s facility with spoken and written language.
Consider further the creative elements of intellect that express themselves in forms of art or inventiveness. Still to this day, Thomas Alva Edison has more patents than any other human being. He stated that genius is 99 percent perspiration and only 1 percent is inspiration.
And then there are the inexplicable and fascinating cases of persons affected with autism or mental retardation who exhibit brilliance in some field as mathematics or music.
And let’s not forget emotional intelligence and intuition. Although, in theory, we can separate personality or character traits such as motivation, persistence and the ability to learn from one’s mistakes from intelligence, they are very hard to separate from any measurement of intelligence or worldly achievement.
Certain aspects of intelligence are accepted as highly heritable, but scientists are a long ways from the identification of the genetics responsible.
One’s childhood environment is believed to moderate the effect of genes. This is called gene-environment interaction (GxE). Several studies have found that socioeconomic status can modify the heritability of children’s intelligence — but the results not consistent.
Consider the effect of culture and the Jewish connection (http://bit.ly/sNLUuD): “In the second half of the 20th century, when Nobel Prizes began to be awarded to people from all over the world, that figure rose to 29 percent. So far, in the 21st century, it has been 32 percent. Jews constitute about 0.2 percent of the world’s population.”
Household values towards education have a strong GxE effect. Chinese-Americans have a reputation for producing brilliant children. The success (or failure) of Asian children is believed to reflect strongly on their parents. The “commodity” of intelligence and worldly success is very highly valued in this culture.
In a study published just last month in Clinical Genetics, 49 participants from Chinese-American communities in the South were interviewed for their attitudes towards prenatal genetic testing (PGT).
Although one out of five Chinese-Americans in the study would not have PGT at all, the majority of those interviewed favored it. One out of five Chinese Americans interviewed reported that they would abort their fetus, if they thought their baby had a defective intelligence quotient, IQ, a genetic disorder or a mental disorder.
Superficial thinking might lure one to conclude that PGT is inherently evil if it can lead to such abuse — but science is not inherently evil. Creation is the work of God. Scientific efforts to understand how God has designed His creatures and universe cannot be inherently evil.
The real evil is the confusion over who owns human life and the misplaced trust in human wisdom to determine the quality of life for another human being.
Next week we shall investigate just how much scientists know about the genetics of “intelligence.” I will share what 23andme reports about my genetic measures of intelligence.
Editor’s note: Nancy@ NancyMillerLatimer.com has worked in scientific research and development for 27 years. She blogs at NeuronalBeauty.BlogSpot.com.
Published in The Messenger 5.02.12