DNA and Intelligence: Separating fact from fiction

Does our DNA predetermine our intelligence? Are there any scientific studies about that? 

Intelligence is challenging to study, partly because it can be defined and measured in different ways.

Elements of intelligence include the ability to:

  • Reason;
  • Plan; 
  • Solve problems; 
  • Think abstractly;
  • Understand complex ideas. 

So, how do you study all of them at once? In this article, we’ll talk about DNA and intelligence: separating fact from fiction.

Let’s go!

Does DNA matter in our intelligence?

Studies have not found any genes that create a significant difference between the intelligence of groups or individuals. 

This points to the likelihood that genes affect specific areas of intelligence rather than intelligence as a whole. 

There has been evidence that genes are connected to specific aspects of intelligence, such as linguistic ability and memory.

Is it true that our environment influences our intelligence?

There is a significant link between environmental factors and intelligence. 

In the early stages of life, our intelligence is greatly affected by our home environment, education, caregiving, and healthcare.

However…

Scientists are still debating if intelligence is genetic or environmental.

What is the IQ?

The most common way that intelligence is measured is using the intelligence quotient (IQ).

The intelligence quotient (IQ) is a person’s score in comparison to their age group from an age-appropriate test that measures verbal, numerical, and abstract abilities.

This score was used in studies that proved how intelligence was connected to factors such as prenatal care, nutrition, and social status.

For genetics, there has yet to be an answer to the question of just how much genes can determine intelligence.

In practice, people use IQ scores to predict a group or individual’s performance in academic and work contexts, as well as assess their cognitive development. 

How does the IQ gene look like?

There is no singular “IQ gene,” but the study published in Nature Genetics was able to determine around 22 specific genes that affect some aspect of intelligence. 

The study analyzed 78,000 people’s individual IQ scores and genomes. 

That’s a lot of people!

The 22 genes implicated in intelligence are the genes involved in regulating the growth of neurons.

10 facts about intelligence

DNA and intelligence 1 DNA and Intelligence: Separating fact from fiction

Even with all the different definitions of intelligence, researchers agree that intelligence is a potential rather than a fixed ability.

It is potentially affected by our physical brain’s development and shaped by our material conditions. 

Here are some facts about intelligence you might not have heard of.

1) Left-handers are not more intelligent than right-handed folks

Famous left-handed individuals like Leonardo da Vinci and Isaac Newton played a big part in creating this myth. 

It was believed that their intelligence was due to their dominant hand being the one that is non-dominant in most people.  

Right-handed people fret not!

Experts have measured students’ school abilities and found that left-handed pupils have more or less the same academic achievement as their right-handed peers

Some evidence even indicates that right-handed people might have a higher IQ!

Whether one is left-handed or right-handed may indicate which lobe is dominant, but intelligence involves the whole brain rather than one lobe or the other.

2) Atheists are not more intelligent than believers

Atheists being more intelligent than theists is another myth that spread over the internet in the past ten years.

More than 200 studies were conducted worldwide, yet none showed a significant difference in the intelligence of atheists and theists. 

It is no surprise that one’s personal choice regarding religion is unrelated to intelligence. 

3) IQ tests are limited…surprise, surprise!

Even though IQ tests are administered and developed by licensed professionals, no test is without limitation. 

IQ tests only show how many answers an individual got correct in relation to their peers.

This is not enough information to conclude about one’s intelligence levels.

The test needs to take into consideration other factors that show how or why these differences in scores came to be, such as cultural backgrounds and material conditions. 

If taken out of context and misused, IQ tests may enforce discrimination against marginalized groups like ethnic minorities, women, and differently-abled individuals. 

These types of biases could further keep people from their intellectual potential.

At the same time, IQ tests can be narrow-sighted as it does not measure other cognitive abilities like creativity or wisdom. 

4) There is more than one gene behind intelligence

It is not uncommon to believe that intelligence is based on biology or genetics.

But as we’ve already discussed, intelligence is not a single, but rather a group of genes.

Many believe that intelligence is ultimately a social construct. Therefore it has no singular biological basis.

Rather, intelligence is likely a result of a set of processes related to developing the different brain areas, how well they work, exposure to certain environmental elements, and other factors.

5) There are 8 different kinds of intelligence!

According to Howard Gardner’s theory on intelligence, humans possess not one but eight types of intelligence.

This concept called the Theory of Multiple Intelligences, assumes that there are eight areas of intelligence that individuals excel to different degrees.

Gardner defined eight types of intelligence. Here they are:

  1. Verbal-linguistic;
  2. Logical-mathematical;
  3. Visual-spatial;
  4. Musical-rhythmic;
  5. Bodily-kinesthetic;
  6. Intrapersonal;
  7. Interpersonal;
  8. naturalistic.

However, other theories of intelligence have all found that there is a basic form of unitary intelligence labeled “G” or “General Intelligence.”

6) We use way more than only 10% of our brains

A lot of science fiction has depicted human beings as only using 10% of their brain and that learning to use the whole brain could unlock significantly more intelligence. 

Brain scans have revealed that this is simply untrue. The scans show that almost all parts of the brain are active at any given time.

This myth is one example of why we should not believe everything that we see on TV.

7) There is no more intelligent race than the other

DNA and intelligence 2 DNA and Intelligence: Separating fact from fiction

From the racists’ perspective, pseudoscience tried to show that white people were significantly smarter than other races. As with any other racist claim, this one was proved ro be right by the very first tests.

Duh.

IQ tests affirmed their claims by showing that black people had, on average, 10 to 15 points lower IQs than white people. 

But it was pure speculation.

The first versions of the test had a significant cultural bias that worked against people from different cultural backgrounds. 

When the test was reviewed and rectified, they no longer found a significant difference in IQs between people of different races.

I’m surprised this assumption was even made in the first place!

8) Men are not smarter than women…quite the opposite!

Recent intelligence tests have shown higher IQ scores for women. But it was not because of a real increase in their cognitive ability. 

Similar to the case of racial differences, the first versions of the IQ test were developed by men who made them with a significant gender bias.

Women did not receive the same type of education as men at the time. And considering that the questionnaires incorporated aspects traditionally taught to men, such as mathematics, you can see how the bias was developed.

Since men and women were given the same education, performance on these tests between men and women has become progressively more equal.

9) Mind games do not increase intelligence

Puzzle-like games are believed to increase intelligence.

Unfortunately, this is not the case, as IQ points do not increase regardless of the number of games one plays. 

However, these games can be useful for people who want to spend time testing their intelligence

They are especially helpful to those who suffer from Alzheimer’s, dementia, or a form of brain damage.

10) Brain plasticity and intelligence are linked

It has been known that intelligence remains stable throughout one’s life, and IQ points are unlikely to increase significantly.

However, new studies have shown that the brain can still grow and develop, especially if we promote neuron plasticity.

How can we do that?

By continuous learning and trying new things!

These findings dispel the long-held belief that neurons can no longer multiply after a certain age.

To summarize

Multiple research concluded that the nature-versus-nurture debate is a false dichotomy.

Science has shown us time and time again that a single factor does not determine our intelligence but rather multiple processes. 

That’s why we should not stop learning and always strive to develop our brains! 

Even if you heard that intelligence is set in stone or left-handed people are less capable–just do your own thing! Science shows we all have way more potential than we think.

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Tina Fey

Tina Fey

I've ridden the rails, gone off track and lost my train of thought. I'm writing for Ideapod to try and find it again. Hope you enjoy the journey with me.

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