I have always wondered whether intelligence level is inherent, meaning you are born with a certain natural learning capability, or learned, meaning if you work hard enough and want to have a certain level of intelligence, you can attain it.
We know that intelligence is a complex trait, so it is “influenced by many different genetic and environmental factors.” And we also know that we do get a certain amount of our intelligence from our parents. But is an individual limited to what they’re given by their parents, or does everyone have a clean slate when they are born, able to shape their own experiences and level of intelligence?
The first bit of research I looked into in an attempt to get a clear answer to this question was a study involving identical twins and if they share the same amount of intelligence. Identical twins have 100 percent shared DNA, so their intelligence levels are very similar. A study shows that even when raised in separate households, the identical twins still have extremely similar IQ levels, which means we can gather that genetics holds more weight on the intelligence scale than where one was raised, but environment is still a key factor. (Fraternal twins are different. Fraternal twins are just like regular siblings, and siblings can have different IQ levels.)
Genetics can largely come into play with brain size, but there is no proof that brain size is linked to intelligence. Molecular biologist Robert Plomin says that heritability of intelligence is around 50 percent and rises to 75 percent by late adolescence because “family influences on cognition are deemed to diminish throughout development” (Plomin). Yet there is no proof of causation here. The Flynn Effect states that cognitive development is flexible (some intelligence being fluid while some aspects being set in stone, determined by IQ tests). Members of the American Psychological Association task force underscored in their 1995 report that “heritable traits can depend on learning and they may be subject to other environmental effects as well. The value of heritability can change if the distribution of environments (or genes) in the population is substantially altered.” So environmental aspects, such as how many years of schooling someone has, plays a large part in their intelligence level, as well as genetics does. There is still a lack of evidence for scientists that attempt to prove that it is one hundred percent genetic. There are many studies that prove, genetics aside, that environment plays a major impact in a person’s intelligence, such as the study with Genie, a girl who was isolated in her room for the entire beginning of her life until the age of 13.
So we ruled out that intelligence is, in fact, inherent, and you’re born with it genetically from a combination of your parents because of the identical twins study. Intelligence can also be passed down from earlier ancestors than just your parents, and that’s how some children, when they become adults, can outsmart their parents’ intelligence. But environmental situations play a huge role in someone’s intelligence, such as factors like they way the child was raised, attention from parents, schooling, wealth, and many other factors. So it’s not necessarily one or the other, but a combination of both factors that makes up our intelligence level and our intelligence capabilities. But I believe there should be a study conducted where both parents take an IQ test and so does their child. Would the child have an average of the parents two IQ levels, or would the child be more influenced by environmental factors than just the average of the parents intelligence levels? This would also prove that intelligence can be passed down genetically from previous ancestors.
I also have an anecdote from my own life experience. My Dad is very good with numbers and math and my Mother is not. She is “people smart.” She knows people very well and has what is called emotional intelligence (EQ). She’s intelligent, just in a different way. I’ve never met someone who can read people as well as she can. My sister’s very much come from my father’s side; they got the science/math brain while I…unfortunately did not. I am more from my mother’s side. Does that mean my older sisters got more intelligence than I did?
Not necessarily. They are more talented in the area of mathematics and reasoning while my strength lies in journalism, public speaking, reading comprehension. If one is born with a certain capacity for “book smart” intelligence, is one born with emotional intelligence just the same or is that learned? Does this social fluency have more of a weight on experiences and environmental circumstances? I would guess that emotional intelligence can be learned better than intelligence can be learned, but it does not come naturally to everyone. For some people, person-to-person interactions can be more challenging than calculus. The question of emotional intelligence being learned or genetic is a more difficult question to answer, and not as many studies have been performed on this topic. Many people argue that someone who lacks emotional intelligence can understand and develop the skill, while people don’t tend to argue that point for “book smart” intelligence. Stephan King argues that while you cannot turn a bad writer into a good writer, you can turn a competent writer into a good writer (Stephen King: On Writing). Writing airs on the side of emotional intelligence and being able to communicate with people, and he believes that it is not learned so much as inherited. This article expresses that the EQ level you are born with is firm, but not rigid. It is influenced by early childhood experiences and genetics, the article claims. Some people who lack this type of personable intelligence are also just better at learning EQ than others.
So now, my final question after coming to the conclusion that intelligence is mostly inherited, but also has to do with childhood development and environment- is there no hope for people who are born with an average or slightly below average IQ level? After doing this research, no. Anyone can, if they dedicate their time and work hard enough, can achieve what they set out to achieve, it may just come more difficult to them than someone who was born with a higher level of intelligence. This is seen a lot on college campuses; students can all succeed, some may just need to work a little harder at it, is all.