What is the difference in IQ and values of 'identical twins from different countries and families'?

Among twins,

identical twins , which are born by dividing one fertilized egg, basically have the same genetic information, and not only have the same gender and blood type, but also have high similarities in physical ability and academic ability. It is said. How much difference was made by the environment and family of twins who were such identical twins but died when they were only two years old and were raised by different families in completely different countries, 'Korea' and 'America'. The results of the research conducted have been announced.

Personality traits, mental abilities and other individual differences: Monozygotic female twins raised apart in South Korea and the United States --ScienceDirect

Psychologists found a 'striking' difference in intelligence after examining twins raised apart in South Korea and the United States
https://www.psypost.org/2022/05/psychologists-found-a-striking-difference-in-intelligence-after-examining-twins-raised-apart-in-south-korea-and-the-united- states-63091

A Pair of Twins Grew Up in Different Countries, Then Scientists Compared Them

Various human characteristics and personalities are strongly influenced by genes. For example, IQ has shown that 80% are hereditary , and twins with the same gene get almost the same score in the cognitive test. However, humans are not only shaped by genes, and the surrounding environment also affects them, so we need to consider the effects of both genes and the environment.

This time, the research team focused on a pair of identical twins born in South Korea in 1974. The two had been raised together by their parents for some time, but by the time they were two, one of the twins went missing in the market and was taken to a hospital 100 miles from their parents' home. I was exposed. The real parents searched for the lost child, but could not meet it, and the orphaned child was eventually adopted by a couple living in the United States.

After that, the two were raised in completely different countries and families and grew up to be adults, but when American twins provided DNA to the 'program to track missing children' in South Korea, they went to South Korea. It turns out that there are twins who are separated. The two reunited in 2020, more than 40 years after they separated. The research team then contacted the twins and asked them to conduct a series of cognitive tests and interviews.

Nancy L. Segal, a professor of psychology at California State University, said, 'I have been studying separately grown identical twins for many years. They have genetic effects on human traits and environmental. It's a simple and elegant experimental method to isolate the effects. This case was unique in that the twins were raised in different countries. '

The research team evaluated the twins' family environment, general intellect, non-verbal reasoning ability, personality traits, values, self-esteem, mental health, job satisfaction, medical history, etc. I did it.

As a result, it turned out that the twins not only grew up in countries with different cultures, South Korea and the United States, but also had a significantly different family environment. The twins who grew up in South Korea grew up in a family with a supportive and cohesive atmosphere, while the American twins grew up in a family with strict and religious ideas and conflicts between families.

Despite having the same gene, there are significant differences in the cognitive abilities of twins, and twins raised in South Korea scored significantly higher in intelligence tests on perceptual reasoning and processing speed, 16 than American twins. The point also recorded a high IQ. We also found that twins raised in the United States had more individualistic values, while Korean twins had more groupist values.

However, we also know that the twins were similar in character to each other, even though they grew up in completely different cultures and environments. Both had a strong tendency to be honest, but a weak tendency to be neurotic, and although their jobs were different from those of government officials and cooks, their job satisfaction was similar. In addition, the twins showed similar mental health profiles, and their self-esteem scales had the same score.

'Genes have a broader effect on development than we imagined, but environmental effects are still important,' Segal said, discovering twins with similar circumstances. He insisted that he needed to study.

in Science, Posted by log1h_ik