Do you believe that I am an introvert (IMO I am) because of life experiences, or do you believe I’ve had the life experiences I’ve had BECAUSE I’m an introvert?
Ahh, the “nature v. nurture” debate. There is no real consensus, but I believe that most opinions fall somewhere in the continuum of it’s some combination of both - with the major debate being where the balance is.
Sua
We’ll know for sure when we either[LIST=A][li]isolate the genes that code for introversion, or[/li]demonstrate that no set of genes codes for instroversion (which will take a heck of a lot longer).[/LIST]
I remember reading in my personality textbook (either The Personality Puzzle or Pieces of the Personality Puzzle, but I don’t remember the author) that the brains of introverts tend to take in more information than the brains of extroverts. So there may be some biological basis for it.
Ahhhh, so extroverts like the world around them because they don’t notice all the bad parts! 
Wow I feel smarter already.
Then again, not all introverts are necessarily pessimistic. That is, you could be extroverted and still hate the world, couldn’t you? Or introverted and like it…etc.
Anecdotally, my brother and I (just over a year apart) were reportedly opposite from birth. I was sneaky and tried to hide what I was up to and my brother was out there and more sociable. Growing up I was the fearful shy good girl while he ran wild.
We have developed into adults who are much closer in disposition; I have learned how to be more comfortable in social situations and can be as at ease as he. We both attribute our “issues” to how we were raised but there was a basis for our behavior growing up from the beginning.
So, what Sua said. 
I was thinking:
Say you took DNA from Hitler, Mother Teresa, Castro, a serial killer, Bloody Mary, Cleopatra, and Octavian (I just chose the first few famous, really important people with defined character that came to mind- I’m sure you could think of more) and cloned them, and raised the clones in different conditions than the original. Would they grow up like to turn out like the original?
Take Hitler, for example. If he had grown up in a more tolerant family, would he have still been so eager to kill anyone who wasn’t perfect?
And what about Mother Teresa? If she had been raised in a very wealthy family, would she ever have been able to learn to live the selfless, poverty-stricken life she chose?
And Bloody Mary (Henry VIII’s daughter)- would she have been so cruel if not brought up in a world of court intrigue fearing for her position and life?
Cleopatra- Would she have ever become the scheming woman that she did without the need to fight for her throne, watch for poisons, and even go so far as to sleep with Caesar for his support?
What do you all think?
The way introverts and extroverts work is essentially as mentioned above. Introverts take in more information about their environment than extroverts.
What this means in practice though is that in a crowded party, for example, the introvert has to process gobs more information than the extrovert standing right next to them. So in a short time the introvert get completely shagged out from all the extra work and goes home.
Likewise sitting in a quiet room with maybe some soft music playing the introvert has a pleasant level of stimulation. The fish are swimming in their fish tank. The sun is dappling the floor. Stravinsky is flowing out of the speakers and all is right with the world. The extrovert sitting in the same room is meanwhile going nuts because “Nothing is bloody happening!” In fact the extrovert is spending energy trying to tolerate this lack of stimulation.
While life experience may effect a persons behavior. It is debatable whether any experience or learning will change this fundimental way that a person interacts with their environment.