Author: Rebecca Jade Williams, Ph.D.
When I think of people who are highly intelligent- for instance, people who demonstrate great verbal skills, or have a knack for mastering musical instruments- describing them as ‘naturally’ gifted seems rather, well, natural. But when we make statements such as ‘naturally’ gifted, we are making the assumption that skills and intelligence are hard-wired, or determined by genetic makeup. How true is this? Is our intelligence really something that we are born with?
When scientists ask such questions about genetics, they often look to twins. Twins are incredibly valuable to science because they can tell us how important genetics are to different traits. Researchers compare between identical twins, who share 100% of their DNA, and fraternal twins, who share 50% of their DNA, to determine how strongly genetics contribute to certain traits. They can do this because all the studied twins are raised in the same family, and have the same access to resources and opportunities. Let’s say we have a group of people consisting only of pairs of twins, and get them to all perform the same task. If the scores of identical twins are more similar to one another than fraternal twins, then we say that this trait is influenced by genetics. The larger the difference between identical and fraternal twins, the greater the genetic contribution.
What exactly do twin studies say about intelligence? Well, this has been fiercely studied and debated. For a long time, it appeared that about half of our intellectual abilities are attributed to genetics. But more recent work hints that this may be an underestimate- in fact, a recent, very large research study looked at more than 11 000 pairs of twins and suggested that about 62% of our academic achievement is due to our genetics.
Twin research shows that a large amount of intelligence is inherited, but does this mean that we are limited in what we are able to learn? This question haunted me when I first started university. I was never that great at math; I struggled with it and tried to spend as little time on it as possible. When I decided to study psychology, I became devastated to learn that psychologists need to be very good at statistics. In my statistics class, the small things that seemed to come naturally to everyone else did not come naturally to me. I resigned myself to the fact that I was naturally bad at math, and that this lack of ability was inherited. No other person in my family was good at math- in fact, I was the first to finish high school and go to university.
Accepting of my destiny, I spent my first years of university doing whatever I could to achieve the minimum passing grade in statistics, and shifted attention to the subjects where I didn't have a natural disadvantage. However, with time things started to change; after a lot of reading, help from others and deep thinking, I actually began to enjoy statistics class. Now I had to contemplate a new reason: that perhaps I lacked numerical ability because when it came to math, I never truly tried.
While research does support a strong genetic influence to our intelligence, this does not mean that we are limited in what we can learn and achieve. In fact, research indicates that how we perceive our intellectual abilities is very important, arguably as important as our genetics. We know that children perform better at school when they and their parents have a ‘growth’ mindset, which is one that believes skills are developed and honed, as opposed to a ‘fixed’ mindset which is, unfortunately, what I had in regards to my own mathematical ability. Luckily, a growth mindset can be taught, and I know this not only from my own experiences. Studies have shown that children with fixed mindsets improve in their academic abilities after they are taught to approach learning in terms of a growth mindset.
At the least, these findings should make you think twice when you describe someone as naturally gifted, or blame the lack of a skill on not having the right parents. Genetics do account for a proportion of our intelligence, but it is not the complete story. Our overall success depends on many factors, including our approach to learning.