The Genetics of Human Intelligence

Fagjun | Published 2017-05-24 09:44

Scientists have found 40 new genes that have some bearing on human intelligence and IQ.

There were previously only 12 known genes that influence intelligence. With this new discovery, the number now stands at 52. However, scientists think that there are hundreds or even thousands of genes that have something to do with intelligence. Here's the thing, though—even at the hundreds or thousands, these genes actually have a very small influence on cognition. The 40 newly discovered genes themselves account for only about 5% of variations in human IQ.

The rest of these intelligence genes have yet to be found. Though these genes don't have much of an impact on intelligence, they do perform an important function.

Does Human Intelligence Have a Blueprint?

Genes provide the blueprint for the neurons in our brain.
[Photo by Sebastien Gabriel]

Of course, genes aren't the only factors that determine a person's intelligence. After all, knowledge and the ability to reason develop as we grow. However, these genes are the blueprint that guide the formation of neurons and neural pathways. The genes are also the blueprint for the synapses that connect neurons as well.

Thus, these genes may not have much of an influence over human intelligence, but they do play an important role in the brain.

Researchers gathered 60,000 adults and 20,000 children as participants and identified genetic markers for intelligence. These participants belong to 13 different groups of European descent. Among these participants, the researchers found the aforementioned 40 genes relating to human intelligence.

These new genes also have something to do with autism, better academic performance, a larger head circumference, and a longer life.

The researchers then blocked the function of these new genes in mice to see how the genes affect brain function. This same technique can work using human skin cells, the researchers say. They can fashion human brain neurons from skin cells and test the effects of each of the genes then. However, before this can happen, scientists first need a more detailed, perhaps more complete idea of the genetics of human intelligence.

When this happens, we can then learn more about how mental conditions come about. Of course, this isn't the only thing that can arise from these findings.

Potential Applications

Once we know more about human intelligence, knowing of course doesn't just end at simply knowing. This knowledge will be used in one way or another. If we know more about the genes that influence intelligence, one possibility is that of the creation of IQ-boosting drugs. These drugs can help aging individuals with declining cognitive skills and protect them from harm or scams.

Another possibility is screening embryos not only for genetic health conditions but also for intelligence. However, this possibility is still quite far off in the future, if it ever does become a reality. Genes can also help educational institutions tailor instruction to students based on their genetic makeup.

Professor Danielle Posthuma, lead author of the study, nonetheless asserts that genetics don't “determine our lives”. Even so, knowledge of genetics and how they influence human intelligence will definitely have its benefits. With more research and insight into the matter, we'll be able to see the ways we can make our genes work for us.

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