Identical Twins Raised in 2 Different Countries Have Massive IQ Difference

By: Georgia | Last updated: Oct 22, 2023

For many years, experts have debated whether intelligence is largely influenced by genetics or by the environment. This complex debate centers on the influence of nature (genetics) and nurture (environment) on human intelligence.

Both elements have been shown to play vital roles in shaping intelligence, and recent studies continue to shed light on their respective impacts.

A Tale of Two Continents

A particularly compelling study examines separated identical twins; one raised in the United States, and one raised in Korea. Despite having identical genetic profiles, these twins, exposed to distinctly different environments, demonstrated significant variations in IQ. 


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Specifically, the twin raised in the U.S., surrounded by ample educational opportunities, scored an IQ of 140. Conversely, the twin in Korea, who faced economic challenges and had limited educational resources, had an IQ score of 90.


The Power of Genes

Twin studies have consistently been instrumental in the exploration of genetic influences on intelligence. Identical twins share all their genes, as opposed to fraternal twins who share around 50%. 


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Consequently, identical twins often exhibit more similar IQ scores than fraternal ones. However, it’s important to note that no single “intelligence gene” exists. Instead, numerous genes interact, and their expressions can be affected by environmental factors.

The Role of the Environment

Environmental elements also profoundly influence IQ. As an illustration, children who attend school regularly perform better in IQ tests. Additionally, longer breastfeeding durations have been linked to slightly higher IQs in some studies. 


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Notably, research also indicates that first-born children tend to outscore their younger siblings in IQ tests, possibly due to the focused attention they receive from parents during their early years.

In Search of Answers

In conclusion, while genetics undoubtedly plays a role in determining intelligence, environmental factors are equally significant. The intriguing case of the separated identical twins serves as a testament to the crucial influence of upbringing and environment on intelligence. 


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As studies progress, understanding the interrelation of genetics and environment remains pivotal to deciphering the intricacies of human intelligence.