Identical twins raised in US and Korea have massive IQ difference

Tuesday, 06/02/2024, 16:23 (GMT+7)

Unlike common twins with quite similar IQs, the case of these identical twins confuses scientists with their extremely large IQ gap.

The story of identical twins raised in the United States and Korea with a significant IQ difference has captured the attention of many people.

These twins were separated and raised in two different countries as toddlers.

The astonishing gap in their IQ scores has sparked curiosity and raised questions about the factors influencing intelligence.

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A pair of identical twins confuse everyone with their large IQ gap. Image Credit: Getty

The identical twins were separated as toddlers due to one of their missing

The twins were born in Seoul, Korea in 1974, but they only lived together until the age of two.

During a visit to a market, one of the girls got separated and went missing. She was eventually found by strangers and taken to a hospital approximately 100 miles away. 

Later, she was placed with a foster mother and had no memory of the separation. Eventually, the lost twin was adopted by a family in the United States.

In 2018, the lost twin decided to participate in a program in Korea that aimed to reunite family members.

As part of the process, she submitted her DNA sample, which was then entered into the system. 

In October 2020, she received the astonishing news that she not only had a twin but also another brother and sister.

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Identical twins are separated after being lost at the market. Image Credit: Getty

IQ tests are tested on identical twins

After the discovery, researchers from the United States and Korea conducted tests and interviews with the twins to learn about their intelligence, personality, mental health, and medical history. 

They found that the twins had similar personalities, suggesting genetics played a moderate role in shaping their adult personalities.

However, the twin raised in Korea described her family environment as peaceful, while her sister in the United States faced conflicts and the divorce of their foster parents. 

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The twins were determined to have identical personalities. Image Credit: Getty

Moreover, both twins exhibited conscientiousness, indicating their motivation, organization, loyalty, and desire for achievement. 

These shared personality traits emphasize the influence of genetics in shaping an individual's character.

Identical twins have significantly different IQs

However, the researchers were confused about the "significant difference" in their IQ scores.

Previous studies on identical twins have consistently shown minimal differences in IQ, usually within a range of seven points.

However, in this specific case, the twins raised in distinct countries and environments showcased a remarkable contrast in their intellectual capabilities.

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The twins have a huge IQ gap instead of having a normal IQ score of no more than 7 like other twins. Image Credit: Getty

While the sister raised in Korea has quite high IQ scores, the one raised in America has IQ scores 16 times lower.

These initial tests cannot accurately determine whether different maturation affects their IQ.

However, a study shows that an older sister who grew up in the US may have poorer cognitive ability than a younger sibling as she experienced three traumatic events in her life.

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Scientists believe that environmental factors and the maturation process can affect the intelligence of twins. Image Credit: Getty

In addition, living environment is considered a factor that affects IQ.

While the older sister has an individualistic perspective due to living in America, the younger sister has many collective values when living in Korea.