How Genetics Affects IQ
So much for the days of studying hard to be smart. There are a growing number of studies presenting evidence that our IQ may actually be largely genetic.
IQ in adults is almost as heritable as height. Studies have shown that children of the same parents have similar IQ’s, whereas an adopted sibling will not have the same IQ even though the child is raised in the same environment. In fact, even if biological siblings are raised in different homes, their IQ’s will remain similar.
This does not, however, mean they will do anything productive with their intelligence. For most of his life, the smartest man in the world, Chris Langam, a man who tested off the charts of modern IQ tests, worked as a manual laborer and a bouncer at a bar.
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Many different genes affect IQ. A recent study showed that no single gene makes a marked difference in an individual’s IQ of more than a fraction of a percent, but the cumulative total of all the genes that affect intelligence can impact your IQ by as much as 20% or more.
This means it won’t be a simple thing to order a high IQ baby from your genetic doctor in the future. You may actually be better off just buying the sperm of a certified genius. (Please use our contact form for all sperm donation inquiries.)
Genes that affect IQ may not increase your IQ directly. Geneticists haven’t found an IQ gene; instead there are dozens, or possibly hundreds, of genes that have an impact on brain development, many in unexpected ways. For example, gene mutations causing disorders and diseases can also indirectly lead to increased neural activity, so certain genetic mutations and diseases might actually make you smarter.
Children’s IQ’s are affected much more by their environment than adult IQ’s. Once you reach adulthood (post-adolescence) your IQ is pretty much set, which can be attested to by that one guy we all know who smokes pot every day, drinks all night, and then wakes up and aces his GMAT. A child, however, can have their IQ stunted by poverty, abuse, neglect, and other negative environmental factors.
There is actually some evidence that video games can increase IQ in children, particularly fluid intelligence (the ability to solve problems in novel situations), but not if they play Zynga games.
Ashkenazi Jews: The Most Genetically Intelligent People On Earth
The highest IQ of any ethnic group is Ashkenazi Jews, averaging between 112-115. In comparison, the average IQ of Europeans is 100. (NOTE* Researchers at Harvard have also tried to test the IQ of monkeys, but ran into trouble deciphering which test belonged to which monkey because they couldn’t sign their names on the test sheets.)
This fact is interesting for genetic researchers because Ashkenazi Jews are over-represented in high positions in society for the size of their ethic group, while other Jewish ethnic groups are not. More than 25% of all Nobel Prizes, including Albert Einstein, have been won by Ashkenazi Jews, and over 50% of chess world champions are Ashkenazi Jews.
In their book, “The 10,000 Year Explosion”, Gregory Cochran and Henry Harpending suggest that this group of Jewish descendants developed their high IQ’s after they moved into Northern and Eastern Europe during the Middle Ages and mostly worked in intellectually stimulating positions as merchants and money lenders (Christians were not allowed to lend money for many centuries). The social isolation of this Jewish ethnic group in Christian Europe for hundreds of years (they were not allowed to intermarry) allowed the natural selection of these intelligence traits to occur.
It’s not all wine and roses though. Ashkenazi Jews also share a much higher rate of certain genetic diseases and disorders including Tay-Sachs disease, Gaucher’s disease, and certain kinds of breast cancer. As mentioned earlier, some of these diseases may actually help increase their IQ.
In general, IQ in America has been rising at a rate of over .3 points per year. Proof of increasing IQ, however, is becoming more difficult to find…
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