Personality Is Inherited

Kim Ooh-ri, a young mother, had a lot of worries after talking to her daughter’s kindergarten teacher. The teacher told her that her daughter was too quiet and liked to play alone. She never wanted her child to inherit her introverted personality.

According to a recent report, introverted and extroverted personalities are usually inherited from the parents.

The team, led by Dr. Heo Yoon-mi of the Seoul National University Medical Research Center, conducted personality research on 765 pairs of teenage Korean twins. The result showed that more identical twins had similar personalities than fraternal twins. This indicates that personality has a lot to do with genes.

The team measured personality similarities on a scale of 0 to 1. The more similar, the closer to 1 the figure was. The figure of introverted and extroverted personalities was 0.51 for identical and 0.25 for fraternal twins. This indicates that if parents have an outgoing and social personality, their children are highly likely to inherit such a personality.

Adventurous personalities (0.49) and nervousness (0.38) were also highly affected by genes. The research results will be published in the April issue of the international journal Twin Research and Human Genetics.

Lee Na-ra is worried because her daughter is too outgoing. She herself, however, has an introversive personality. How could this be? This is because of the various effects between genes that act to form personalities.

The possibility of known genes affecting personality is 1.5 to 5%. For example, the possibility of the curiosity gene DRD4 affecting the formation of curiosity is merely 3%. That is, not all people with DRD4 genes have lots of curiosity.

This is why tests that determine a personality by just few genes are inaccurate. The patience gene HTR2A and teamwork gene CNRA4 affect only 5% of personality formation. “The other 95% that forms teamwork is a result of interactions between many genes,” said Dr. Heo. Even when inheriting the same set of genes, a child’s personality can differ by interactions between genes.

This is why siblings have different personalities. For example, one fraternal twin was measured 9 in introverted and extroverted personality score, and the other a 0. The twins had opposite personalities.

Environment is also important in personality formation. Any child can grow up to be a misguided teen when growing up in an unfortunate environment. In this case, they turn out to be okay by simply changing the environment. However, those who have anti-social genes are difficult to change.

The team explains that it is difficult to change children’s personalities by education at home. “A child’s personality changing overnight by going to private institutions is temporary. It is better to develop children’s personalities is a positive way,” said Dr. Heo. The team is looking for more twins for research.

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