A pair of Korean twins separated at the age of two reunite after years and an assessment of their IQ levels gives some interesting insight into how geographical location can play a role in the overall intelligence. Despite all the other differences, the pair had identical scores for self-esteem and mental health profiles. Researchers found that 'the overall configuration of the twins' personality was similar, consistent with the literature on moderate genetic influences on personality in adulthood',
Separated Identical Twins At Birth And Raised In The US And Korea Have Massive IQ Difference
A pair of twins in Seoul, South Korea, 1974 became separated when they were only two when one of the twins got separated at the market.
Now the pair of twins have become a subject of study as their difference in IQ has raised the question if location has anything to do with it?
Despite her parents' appeal to find their missing daughter, she was not reunited with her family and was eventually adopted by a couple from the US.
The twin who grew up in America was unaware of her history and that she had any siblings or a family back in Korea. The revelation came in 2018 when she submitted her DNA to a South Korean program that aimed to reunite lost family members.
In 2020, she discovered she not only had a twin but also an older brother and sister.
As the twins were reunited, they both completed a number of tests that were designed to assess their intelligence, mental health, and medical history; resulting in a groundbreaking study of separate identical twins.
Incredibly, the Korean-raised twin had a significantly higher IQ, coming in at a whopping 16 points over her sister.
The findings of the study, published in the journal Personality and Individual Differences, have contradicted previous research on identical twins, which indicated a difference of no greater than seven IQ points between twins.
Even though researchers are yet to conclude if the difference in IQ is directly linked to their different world locations, it is important to note that the twins did grew up in completely different upbringings.
The sister who grew up in the United States suffered three concussions throughout her life, which can significantly impact cognitive capacity.
The twin raised in Korea grew up in a happy, harmonious home, whereas the US-based twin had a more turbulent childhood.
She also lost her family, found a new one, and eventually had a broken home after her adoptive parents divorced.
However, despite all the differences, the twins had identical scores for self-esteem and mental health profiles.
Researchers found that 'the overall configuration of the twins' personality was similar, consistent with literature on moderate genetic influences on personality in adulthood',
"Notable is that both twins are distinctively high on conscientiousness, indicating that both are purposeful, well-organised, dutiful, and achievement-striving," the research paper said.
This confirms that despite their different upbringings, the two sisters shared similar personalities, values, and approaches to life, highlighting that genetics could have a significant impact on personality.
The interesting case does raise an important question on nature versus nurture? The jury is still out. It's too hard to tell.