The oft cited figure is that 50% of personality is due to genetics and 50% due to environment - but this is the number for society as a whole. Individuals can vary.

By personality I mean the Big Five personality traits which is the personality model with the most empirical backing as of now.

1 hour ago, Otto Kretschmer said:

The oft cited figure is that 50% of personality is due to genetics and 50% due to environment - but this is the number for society as a whole. Individuals can vary.

By personality I mean the Big Five personality traits which is the personality model with the most empirical backing as of now.

There's many more than 5...

On 6/6/2025 at 12:09 PM, Otto Kretschmer said:

The oft cited figure is that 50% of personality is due to genetics and 50% due to environment - but this is the number for society as a whole. Individuals can vary.

By personality I mean the Big Five personality traits which is the personality model with the most empirical backing as of now.

There are a lot of twin studies you will be interested in.

This paper references a few studies and meta analysis.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3868213/#:~:text=Some%20studies%20have%20provided%20evidence,2003).

This article.

https://www.psychologytoday.com/gb/blog/the-baby-scientist/202103/what-twins-can-teach-us-about-genetic-and-environment-influences

27 minutes ago, pinball1970 said:

There are a lot of twin studies you will be interested in.

This paper references a few studies and meta analysis.

https://pmc.ncbi.nlm.nih.gov/articles/PMC3868213/#:~:text=Some%20studies%20have%20provided%20evidence,2003).

This article.

https://www.psychologytoday.com/gb/blog/the-baby-scientist/202103/what-twins-can-teach-us-about-genetic-and-environment-influences

Thanks! +1

Published today- I thought you find of interest.

Institute of Psychiatry, Psychology & Neuroscience (IoPPN) at King's College London, University College London, Queen Mary University of London and 23 universities around the world combined data from up to 21,792 identical twins (10,896 pairs) from 11 studies.

https://www.nature.com/articles/s41562-025-02193-7

 This article gives a summary.

 https://medicalxpress.com/news/2025-06-largest-twin-explores-environment-affects.html

 From the article.

 “They found that genes linked with growth factors—biological molecules which play important roles in neurodevelopment, immune function and the central nervous system—were associated with variation in autistic traits. Genes related to reactivity to stress were linked to variation in depression symptoms. Genes involved in regulating catecholamines—a group of hormones involved in response to stress—were linked to variation in psychotic-like experiences.”

What if an extrovert was raised in a culture and family that values introversion?

Let's say a naturally gregarious, emotionally expressive person is raised from birth in an East Asian family that values self discipline, emotional self control and deriving satisfaction from internal rather than external world. The quality of upbringing is very high but rooted in this specific cultural context. Will such a person become naturally less extroverted? Upbringing does change the brain structurally and functionally.

Edited July 26Jul 26 by Otto Kretschmer

4 hours ago, Otto Kretschmer said:

What if an extrovert was raised in a culture and family that values introversion?

Let's say a naturally gregarious, emotionally expressive person is raised from birth in an East Asian family that values self discipline, emotional self control and deriving satisfaction from internal rather than external world. The quality of upbringing is very high but rooted in this specific cultural context. Will such a person become naturally less extroverted? Upbringing does change the brain structurally and functionally.

History suggests not, a gay person will always shine through...

2 hours ago, dimreepr said:

History suggests not, a gay person will always shine through...

???
Sexual orientation is not a personality trait.
What used to be called 'gay behavior' is ( limp wrist, lisp, flamboyance, etc. - sorry about the obvious stereotypes ), but it is not an accurate indication of sexual orientation

22 hours ago, MigL said:

???
Sexual orientation is not a personality trait.
What used to be called 'gay behavior' is ( limp wrist, lisp, flamboyance, etc. - sorry about the obvious stereotypes ), but it is not an accurate indication of sexual orientation

Historically, gay behaviour just meant flamboyant.

My point was, culture alone isn't enough to suppress a strong/extreme personality type; much like a strong willed sexual "deviant"... 😉

2 hours ago, dimreepr said:

Historically, gay behaviour just meant flamboyant.

My point was, culture alone isn't enough to suppress a strong/extreme personality type; much like a strong willed sexual "deviant"... 😉

Anectodal evidence at least suggest that differences in personality exist even at national level - famously, southern Europeans (Italians, Spaniards, Greeks etc.) are known to be loud and talkative while Nordics (Danes, Norwegians, Swedes, Finns, Icelanders) are known to be reserved, less sociable and more direct in their communication style, though the evidence is just anectodal AFAIK.

12 minutes ago, Otto Kretschmer said:

Anectodal evidence at least suggest that differences in personality exist even at national level

Why?

2 hours ago, dimreepr said:

Why?

I am not aware of any studies specifically about population level personality differences. Thus, I consider the evidence to be merely anecdotal in nature. :)

17 hours ago, Otto Kretschmer said:

I am not aware of any studies specifically about population level personality differences. Thus, I consider the evidence to be merely anecdotal in nature. :)

Then it's just your opinion and therefore has no value in the discussion, besides your conflating a cultural tendency/stereotype with an individual personality. 😉

(The following is a purely hypothetical scenario)

What about subjecting an extrovert to 10-12 months of NKVD level torture? A year of unimaginable suffering that one has no way to escape and being flooded with extreme levels of cortisol all the time would profoundly reshape even the most jolly fellow. Their reward system would become functionally dead and they would live overwhelmingly in their internal world. They would be, for all practical purposes, an introvert.

Edited August 2Aug 2 by Otto Kretschmer

6 hours ago, Otto Kretschmer said:

(The following is a purely hypothetical scenario)

What about subjecting an extrovert to 10-12 months of NKVD level torture? A year of unimaginable suffering that one has no way to escape and being flooded with extreme levels of cortisol all the time would profoundly reshape even the most jolly fellow. Their reward system would become functionally dead and they would live overwhelmingly in their internal world. They would be, for all practical purposes, an introvert.

Some people have a strange relationship with pain, some even genuinely enjoy the sensation, their reward system maybe enhanced, rather than destroyed; it's possible such people would choose to stay and maybe even engage jollily with their torturer. 😉

5 hours ago, dimreepr said:

Some people have a strange relationship with pain, some even genuinely enjoy the sensation, their reward system maybe enhanced, rather than destroyed; it's possible such people would choose to stay and maybe even engage jollily with their torturer. 😉

Fortunately, I would not put anyone through this even if I could despite my own flawed personality.

As a side note, psychodelics interest me a lot, especially their long term positive effects on personality.

https://pmc.ncbi.nlm.nih.gov/articles/PMC6220878/

Edited August 2Aug 2 by Otto Kretschmer

On 7/27/2025 at 4:49 PM, Otto Kretschmer said:

Anectodal evidence at least suggest that differences in personality exist even at national level - famously, southern Europeans (Italians, Spaniards, Greeks etc.) are known to be loud and talkative while Nordics (Danes, Norwegians, Swedes, Finns, Icelanders) are known to be reserved, less sociable and more direct in their communication style, though the evidence is just anectodal AFAIK.

I don't think this is anecdotal evidence. People behave as they learned from a young age in the family home.

If you take a newborn Nordic child (preferably a couple of thousand or millions, to have a large sample rate) and put him/her into an Italian-Spanish family, and he/she (they) despite having stayed all 18+ years in their family would behave like a typical Nordic child raised by Nordic parents, then there would be a topic of conversation.

I think such a “Nordic child” would behave like a typical Italian or Spaniard. Lombardy is the (northern) territory of Italy conquered by Germanic (Nordic) tribes. Later, southern Italy was conquered by the descendants of the Vikings (Normans).

https://en.wikipedia.org/wiki/Norman_conquest_of_southern_Italy

Romans settled Germanic immigrants in Spanish territories:

https://en.wikipedia.org/wiki/Kingdom_of_the_Suebi

Edited August 2Aug 2 by Sensei

2 minutes ago, Sensei said:

I don't think this is anecdotal evidence. People behave as they learned from a young age in the family home.

If you take a newborn Nordic child (preferably a couple of thousand or millions, to have a large sample rate) and put him/her into an Italian-Spanish family, and he/she (they) despite having stayed all 18+ years in their family would behave like a typical Nordic child raised by Nordic parents, then there would be a topic of conversation.

I think such a “Nordic child” would behave like a typical Italian or Spaniard. Lombardy is the (northern) territory of Italy conquered by Germanic (Nordic) tribes. Later, southern Italy was conquered by the descendants of the Vikings (Normans).

https://en.wikipedia.org/wiki/Norman_conquest_of_southern_Italy

Genetics is not the whole thing, there is also epigenetics which is how genes are expressed - and I am interested in how exactly culture and upbringing influences this. As a somewhat extreme example, people with PTSD don't have their genome changed by trauma, the genome remains the same but the epigenetics changes. Yet with strong enough trauma, you can have even a resilient and energetic person be changed into essentially a walking shell barely capable of existence let alone true living.

Edited August 2Aug 2 by Otto Kretschmer

Enough anecdotes will make a data set.
I, myself, was shy and introverted all through my teens and high school; read a lot, wore glasses,didn't participate in sports, and had little social life.
In University, I seemed to have much more free time, was partying in clubs most every night, started working out in a gym the summer I finished high school, got contact lenses, became much more confident, and had an active social life.
I had the same genetic make up during these times, but the circumstances of my environment had changed, whether through my own doing, or external factors.
I know of many other such anecdotes and I'm sure others do too; how many do you need to call it a data set ?

11 hours ago, MigL said:

Enough anecdotes will make a data set.
I, myself, was shy and introverted all through my teens and high school; read a lot, wore glasses,didn't participate in sports, and had little social life.
In University, I seemed to have much more free time, was partying in clubs most every night, started working out in a gym the summer I finished high school, got contact lenses, became much more confident, and had an active social life.
I had the same genetic make up during these times, but the circumstances of my environment had changed, whether through my own doing, or external factors.
I know of many other such anecdotes and I'm sure others do too; how many do you need to call it a data set ?

Introversion-extraversion is not about being shy but about where one draws energy from - introverts are energized by solitude and their internal life, extraverts are energized by social interaction and general interaction with the outside world. Since the distribution is Gaussian, the most common type are actually ambiverts who can draw energy from both.

And yes, I agree with you that a large enough data set does count as evidence. 😃

Edited August 3Aug 3 by Otto Kretschmer

16 hours ago, MigL said:

Enough anecdotes will make a data set.
I, myself, was shy and introverted all through my teens and high school; read a lot, wore glasses,didn't participate in sports, and had little social life.
In University, I seemed to have much more free time, was partying in clubs most every night, started working out in a gym the summer I finished high school, got contact lenses, became much more confident, and had an active social life.
I had the same genetic make up during these times, but the circumstances of my environment had changed, whether through my own doing, or external factors.
I know of many other such anecdotes and I'm sure others do too; how many do you need to call it a data set ?

How many ghost stories would it take to make ghosts real?

5 hours ago, Otto Kretschmer said:

introverts are energized by solitude and their internal life

Some introverts just need validation to become more confident and some extroverts can become less confident with negative validation.

Most people don't really fit into a pigeon hole... 😉

On 7/26/2025 at 12:45 PM, dimreepr said:

History suggests not, a gay person will always shine through...

That's for sure the wrong answer. Well, I can understand the symbolism of what you said, but we are all pretty programmed, would be even more if we didn't have Internet.

First of all historical observations can be skewed depending on source amd because they happened long before you were ever born. Words inadvertedly twist meanings with the writers' subjectivity and knowledge of life or lack of, as much as they help us to learn.

Secondly, it is well known environment modulates gene expression, but we are also social creaturea. As such, it is inevitable that a person raised in a highly reserved and introverted culture will develop and take from the traita they observe around them even when they don't fit too well by nature, simply in order to exist as part of a group. Such would be obvious for an average Italian going to Japan for the first time, for instance. Just look at how many kisses and words interactions locals exchange in these two countries as a standard, or how loud they speak, how often they rouch each other (as all of these measures intro/extroversion) and you'll understand which one is more reserved by tradition rather than by individual nature (where tradition overpowers individual nature, at least when it comes to public displays).

Edited August 6Aug 6 by FreeStyle

20 hours ago, FreeStyle said:

That's for sure the wrong answer. Well, I can understand the symbolism of what you said, but we are all pretty programmed, would be even more if we didn't have Internet.

Did you google it, or think about it?