Are smarts inherited? Research is divided

Is the intelligence of a child prodigy inherited or are geniuses cultivated by their environment?
Recently the Korea Institute of Brain Science released a study on the differences in brain activity between 30 high school prodigies and 30 ordinary teens.
The brains of the 60 students were monitored by magnetic resonance imaging, a technique used to produce high-quality images of the inside of the body, as they were asked a series of easy and difficult-to-solve questions.
According to the report, when solving difficult problems, more areas of the prodigies’ brains showed activity than in ordinary students.
Lee Geon-ho, the institute’s president, said that experiment’s results prove that genius is inherited.
The questions were designed to draw only on congenital intelligence, Mr. Lee said, by using shapes rather than numbers and letters so as to exclude knowledge acquired through earlier education.
Some experts disagree with Mr. Lee on the point that intelligence is congenital. “The ability to understand the relationships of figures could change according to training,” says Kang Eun-joo, a professor at Seoul National University’s medical school.
Mr. Kang suggested that so-called “child prodigies” participating in the experiment could have learned how to use their brains effectively for the test.
Neurologists generally concur that both genetic and educational factors play a role in development of a child prodigy.
As for the question, “Which factor weighs more?” there is a marked split of opinion.
In 1997 the magazine Science published research by Gerald McClearn and his staff at Penn State on “Substantial Genetic Influence on Cognitive Abilities in Twins 80 Years Old or Older.
Mr. McClearn’s staff researched 240 pairs of twins over age 80 on their comprehension, memory and language ability. Their results suggested that genetics had a larger influence on intelligence than environment.
The study showed that while variations in some twins’ intelligence were heavily influenced by the surrounding environment, a comparison of a different set of twins showed intelligence levels varying by inheritance.
The study also pointed out that roughly 60 percent of comprehension and 50 percent of language and memory abilities are influenced by inheritance.
However, a research team led by professor Marian Diamond of the University of California-Berkeley argued that environment is more influential.
The Berkeley team placed several lab mice in different environments and tracked their intelligence development.
One group of mice was placed in a confined space without any toys, and a second group was placed in a larger area but without the toys. The third rodent group was given lots of space plus many toys.
The results showed a clear trend. The brain cortexes of mice in the second group were on average 11 percent larger than those of mice in the first group.
Meanwhile, the third group of mice had a 16-percent larger brain cortex than the second.
The question of whether genius is inherited or environmentally influenced rages on.
Those in academia don’t dispute that both education and environment are vital to development of intelligence in the post-natal period.
Scientists also agree that opportunities to experiment with different games and activities, and growing up in a warm sentimental environment enhances the intelligence of children.
According to one American study, the human brain grows to three times its original size within 30 months of birth; by age 10, the brain weights 90 percent of an adult brain. The brain experiences dramatic growth between 3 and 4 weeks, 7 to 8 weeks, and 10 to 11 weeks after birth.
Additionally, the brain grows again from age 3 1/2 to 4 1/2, 6 to 7, 10 to 12, and 14 to 16. Should a child catch a cold during one of these periods, scientist believe the brain growth process could be hindered because the resulting appetite loss may lead to an insufficient supply of nourishment for brain growth.

by Kwon Hyeok-joo, Park Bang-ju