Do you think introversion and extroversion are genetically based ?

I just received an update from ancestry.com indicating that my dna indicates I’m "probably an introvert" (in fact, I am). Curious, considering that my youngest sister, who comes from the same dna source is very much an extrovert and always has been. 🤔

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Abstraction · 61-69, M

So... Did they base their indication on your ancestry, or your genes? Because you have identical ancestry as your sister, but not identical DNA. They have your sample, not hers.

bijouxbroussard · F

@Abstraction This is what it said:

Introversion & Extroversion
Your DNA suggests you may be more introverted.

Did You Know? Extroverts tend to focus more on the outer world of people and things, while introverts tend to focus more on the inner world of ideas and images.
Science Says
Research suggests that extroverts may more be motivated by rewards than introverts are, potentially due to a difference in sensitivity to a chemical called dopamine.

Genetics and Other Factors

Here’s a breakdown of how genetic and non-genetic factors may influence this trait.

Genetic Factors

For this test, we looked at the DNA of more than 185,000 people who answered a survey question about introversion and extroversion. The participants were placed into one of two groups: people who said they were more introverted, and people who said they were more extroverted. By comparing their DNA, we identified over 10,000 markers associated with introversion and extroversion and created a model that predicts the likelihood of each result.

Other factors

Environmental factors play a role in introversion and extroversion, but the exact size of that role is still unknown.
Unknown genetics
It's likely that some other markers also play a role. As we learn more, there may be new or updated information about this trait.

Abstraction · 61-69, M

@bijouxbroussard Ok this suggests it is on your genetic markers, and that therefore your sister would probably have a different result. Although environmental factors can play a role in introversion/ extroversion as well.

Graylight · 51-55, F

@bijouxbroussard It seems to be stating that the aggregate of those with similar genetic profiles also tend to answer positively to the same question regarding intro-/extroversion. It sounds as id their data has uncovered a pattern, but assumes no causal relationship, merely a correlational one right now.

It's interesting and this all lays the groundwork for future work. I was asked about the length of the 2nd toe on one foot. Bizarre. I think right now we're in a huge data-gathering period and hopefully it'll lead to some exciting insights down the line.