Topic: Is intelligence inherited or learned?
What exactly intelligence mean? Is one’s intelligence presented on the score of
some test, or is it an actual ability on how we adapt with new people, environment,
and so on? We will probably get different answers from dozens of people on how they
defined intelligence. According to (Sternberg & Kaufman, 1998; Wechsler,1975),
psychologists describe intelligence as the skill to study from one’s experiences, gain
knowledge, and use resources efficiently in adapting to new situations or resolving
difficulties. Although psychologists have defined intelligence in a general way, there
are still different views about it. However, the members of the psychology community
have debated the concept of intelligence for decades widely. Some psychologists
dispute that intelligence is a common ability, whereas others assert that intelligence
consists of talents and skills that can be learned. Moreover, psychologists also argue
whether intelligence is inherited or learned. Some psychologists believe that people
behave as they do due to genetic inheritance, known as the “nature” theory. While
some of them trust that behavior and thought of a person can be learned or taught to
do so, this is known as the “nurture” theory. Although Alfred Binet had created a scale
of intelligence in the early 1900s, we saw it as the intelligence quotient (IQ) tests
nowadays. The intelligence quotient (IQ) test is well known to detect and measure
one’s intelligence. Even though these tests are usually dependable and effective, but
they do have their blemish as they have a shortage of cultural particularity. Therefore,
does gene alone determine one’s intelligence or intelligence can be increased through
learning or environmental factors?
Phenotype is known as the gene inherited from a parent to their child, this
usually includes physical properties such as eye color, the color of hair, the color of
skin, and other observable traits. On the other hand, intelligence and behavior are also
characteristics that can be inherited by the parent’s gene; however, these properties
could be affected by learning or environmental factors. As we say the environment,
means the surroundings but it involves not only the living place but also the people
whom we come in touch with, the educational we have acquired, and what we can
learn from. In decades, quite a lot of research studies have existed to define whether
intelligence is inherited or learned. According to (Galton, 1875), Sir Francis Galton was
one of the psychologists who first study the relationship between nature and nurture
with identical twins’ study. Thus, the study of identical twins began to carry out
frequently to investigate whether intelligence is inherited or learned.
One of the famous studies on identical twins was carried up by Dr. Thomas
Bouchard Jr in 1979 that approximately takes up to 10years. This study carries up on
identical twins and non-identical twins to compare their IQ levels and to see the
influence of genetic and environment regarding intelligence. This study is carried out
on twins because identical twins have a hundred percent shared DNA. According to
(Bouchard, David, Matthew, Nancy & Auke, 1990), the outcome of this study shows
that 70% of the difference in the IQ scores was caused by genetic factor, dissimilar
with previous studies that show only 50% of the difference is because of genetic factor.
However, according to (Kolata,1990) the outcome of this study has been disregarded
by certain experts, saying that the data of this study does not overturn many others.
Besides, according to (Kolata, 1990), Dr. Bouchard’s methodology has also been
questioned by a Stanford scientist, Dr. Marc Feldman, saying that the heritability
estimate would cut in half if he had involved relatives of the twins in his study.
Therefore, throughout this study, we can’t see clear-cut evidence to prove that
intelligence is 100% inherited, not learned.
Undeniably, there is some aspect of intelligence is caused by genetics. That
explains why children get a different grade even they are studying in the same
classroom. Another interesting fact is that some people will find themselves doing
better in certain tasks or activities. For example, some people have a natural flair for
drawing, dancing, writing, and so on. They can do these activities well enough even
though they did not receive any proper training before. Therefore, some people are
born with skill and talent that the other does not have and this probably is due to the
genetic factor. However, we can’t ensure that people that are born with “intelligence”
will get great success in their life. There are many examples that people achieve
success in their life even they did not get an excellent grade in school. Their
intelligence is surely not inherited but enhance through unremitting efforts and training.
Thus, they work hard to attain a certain level of intelligence and lead them to success.
According to (Neisser et al., 1996), Members of the American Psychological
Association emphasized in their 1996 report that "heritable characteristics can rely on
learning and they may be affected by the environmental factor as well." Therefore,
how many years of education a person received and what they can learn from their
surrounding will occupy a large section in their intelligence level, as well as heredity.
Thus, psychologists that are trying to prove that intelligence is a hundred percent
inherited, do not have enough evidence to prove it. However, several studies proved
that besides genetic, the environment presents a major influence on intelligence. For
example, a study with a 13 years old girl, Genie. (Cherry, 2020) states that Genie was
isolated in the basement of her home from the age of 20 months. She was a victim of
critical child abuse; she did not have any social contact with others during her whole
childhood. Hence, she did not receive any education before and cause a lack of
language abilities. When Genie was found, she could not eat correctly, walk properly,
or speak in any language. Genie is then admitted to the Children's Hospital in Los
Angeles, where the specialists started to teach her how to speak. Genie had learned
around a hundred words, after staying in the hospital for a few months. Currently, she
rarely speaks but can communicate reasonably in sign language. (Atkinson, Atkinson
& Hilgard, 1983) claims that “a child might have the capability to walk in the sense that
his muscles have already attained the needed strength; he has a good sense of
balance and so on. However, if there is no example of walking were given, he might
not be able to learn to do so”. Children will learn from what they observe around them.
Genie grew up in a violent, oppressive, and closed environment with no positive
examples that she can learn so it causes her to have low language ability. However,
she was able to regain her language ability through learning and it proved that
intelligence could be improved through learning.
For so many years, most people have almost accepted that intelligence is not
malleable. However, many studies have overturned these ideas. These studies have
shown that through learning, people will not only improve academic performance but
also functional intelligence. Moreover, it shows that when we learn something new,
our brain imaging will indicate consistent, measurable changes and growth. This
phenomenon occurs in both children and adults. Therefore, we can see in a famous
study on London taxi drivers that prove intelligence can be increased through learning.
In this study, researchers found out that average adults that are trained to become a
licensed taxi driver in London have a structural change in the brain. This is not an easy
task, because the layout of London is irregular and there are about 25,000 streets to
be familiarized with. Consequently, the trainee must receive multi-year training to
obtain “the knowledge”. From the result, an increase of grey matter in the posterior
hippocampus was found in those who completed the training program while there is
no significant increase within the neural structure was found in those who failed the
training found by (Maguire & Woollett, 2011). Related research has confirmed the
results, for example, learning to read and play music will cause brain structure to
change found by (Stewart et al, 2003). Grey matter is a diffuse network of brain areas,
it is important because it's linked with memory, sensations, muscle control, verbal
expression, and decision-making, among plenty of other functions. According to
(Connor, 2001), Scientists discovered that people that have a larger grey matter in the
brain will score higher in IQ tests. Thus, the increase in the area of grey matter could
increase intelligence.
Although some children have intelligent parents, they are not as intelligent as
their parents are and some children can outsmart their parent's intelligence when they
became an adult. Therefore, it shows that genetics alone does not determine how
intelligent we will be. Our genes will only define the framework of our intelligence,
which means that genes will define the maximum of intelligence we could reach but
not responsible for how intelligent we will be. Many studies have suggested that 50
percent of our intelligence is influenced by genetic factors while the other 50 percent
is depending on environmental factors, but 50 percent of these genetic factors will only
set the framework of our intelligence. (Maltby, Day and Macaskill, 2007) state that
intelligence could pass through generation, but is not the only way because he
believed that the environment is also an important influencing factor. The environment
cannot change the limits inflicted by heredity. Thus, a good environment will allow the
person to reach these limits while a poor one will prevent them from doing so.
Environmental factors that will influence intelligence are the surrounding of a person
grows up in, education, and training received. If a child grew up in a family that
encourages learning, they will probably score a higher score in the IQ test.
Education is the process of learning or the acquirement of knowledge and skills.
A study by (Ritchie & Tucker-drob, 2018) shows that education is one of the most
effective ways to increase intelligence. It shows that the intelligence score is positively
related to how many years of education a person had received. By involving over
600,000 participants, researchers have proved that an extra year of education can
increase a person's IQ by about 1-5 IQ points. Thus, education seems to be the most
constant and long-lasting way to improve intelligence. Besides, young children that
receive training, such as music and chess will probably have higher intelligence. As
they say, learning music will boost verbal IQ, and learning chess will improve the
understanding facility. Besides, according to (Colbert, Tyndall, Roche, & Cassidy,
2018), shows that SMART, a scientifically advanced educational brain training was
proven to improve intelligence levels (IQ). By measured using a standardized IQ test,
SMART brain training could increase 20-30 IQ points. SMART brain training is flexible
to all ages, no matter kids or adults. This brain training will help on improving the critical
cognitive skills, named Relational Skills. These skills are almost the basis of everything
we do in school, work, and in daily decision-making and problem-solving. SMART
brain training helps to simplify learning, exercise brains, and enhance memory recall
to increase IQ. Therefore, intelligence has been proved that it could be increased
through training and learning.
With the evidence that this essay consists of, a conclusion can be made that, it
is hard to classify whether intelligence is caused by inherited or learned because there
are many types of internal and external factors that are contributing to an individual's
intelligence. A person's genetics will decide their intelligence while the environment
provides the opportunity for development. Thus, both genetic and environment play
an important role in contributing to intelligence. However, we could judge that the
intelligence of a person can be increased through learning. Everyone can increase
their intelligence through learning even they are not born to be smart. If they are willing
to spend their time and effort, they can obtain the goal they set, although it will be a
little harder than someone who was born with a higher level of intelligence. Therefore,
a person might inherit a gene of high intelligence, but how intelligent they will become
dependent on the effort they put. So now that we have defined this, there will be simply
no space for limiting assumptions like " My parent was not that smart, so am I” or "I
wasn't born intelligent". We should fully utilize our potential, whether it is hereditary or
not to get great success in our life. Thus, intelligence can be increased through
learning and training even we have already grown as an adult and it proves that it’s
not necessarily one or the other, but a combination of both factors that build up our
intelligence level and our intelligence capabilities.
References:
Atkinson, E.R., Atkinson, R.L., Hilgard, R.C. (January 1, 1983). Introduction to
psychology (8th ed.). New York: Harcourt Brace Jovanovich.
Bouchard, T.J., David, T.L., Matthew, M.G., Nancy, L.S., Auke, T. (Oct. 12,1990).
Science, New Series, Vol.250, No4978, 223-228
Cherry, K. (2020, March 24). The Story of "Genie," a Child Deprived of Nearly All
Human Contact. Retrieved September 30, 2020, from
https://www.verywellmind.com/genie-the-story-of-the-wild-child-2795241
Colbert, D., Tyndall, I., Roche, B. & Cassidy, S. (2018) Can SMART Training Really
Increase Intelligence? A Replication Study. Journal of Behavioral Education. 27,
509–531. https://doi.org/10.1007/s10864-018-9302-2
Connor, S. (5 November 2001). Grey matter does influence intelligence, say
scientists. Retrieved September30, 2020, from
https://www.independent.co.uk/news/science/grey-matter-does-influenceintelligence-say-scientists-9188405.html
Galton, F (1875). The History of Twins, As a Criterion of the Relative Powers of
Nature and Nurture. Fraser’s Magazine 12, 566–76.
Kolata, G. (1990, October 12). Study Raises the Estimate of Inherited Intelligence.
The New York times, p. 22A.
Maguire, E., Woollett, K. (20 December 2011) Acquiring “the Knowledge” of
London’s Layout Drives Structural Brain Changes. Current Biology; Volume 21,
Issue 24, 2109–2114.
Maltby, J., Day, L., Macaskill, A. (2007). Personality, Individual Differences and
Intelligence. Harlow: Pearson Prentice Hall, 2007.
Neisser, U., Boodoo, G., Bouchard, T.J., Boykin, A.W., Brody, N., Ceci, S.J.,Halpern,
D.F., Loehlin, J.C., Perloff, R., Sternberg, R.J., Urbina, S. (1996). Intelligence:
Knowns and Unknowns. American Psychologist. 51:77–101.
Ritchie S.J., Tucker-drob E.M. (2018). How Much Does Education Improve
Intelligence? A Meta-Analysis. Psychol Sci. 29(8):1358-1369.
doi:10.1177/0956797618774253
Sternberg, R. J., & Kaufman, J. C. (1988). Human abilities. Annual Review of
Psychology, 49, 479-502
Stewart, L., Henson, R., Kampe, K., Walsh, V., Turner, R. & Frith, U. (September
2003) Brain changes after learning to read and play music. Neuroimage Volume 20,
Issue 1, 71–83. Retrieved September 30th, 2020 from
http://www.sciencedirect.com/science/article/pii/S1053811903002489
Wechsler, D. (1975). The collect papers of David Wechsler. New York: Academic
Press.