What causes introversion and extroversion?
Nature or nurture?
Most people know whether or not they identify as an introvert, extrovert or an ambivert
Most people have qualities of both
however, people usually tend to lean one way more than the other
Growing up, I'd have to back out of social gatherings last minute
because the idea of having to look this entertained for this long
was draining
As an introvert I've always wondered why I am the way I am
and not the way my best friend is
She could count the people she speaks to on a daily basis on both hands
while I could only count her
my boyfriend
and my cats as the ones I interact with on a daily basis
My best friend on the other hand
could see people every day and not get tired of their company
Why was it so hard for me
but not her?
There had to be an answer as to why people lean one way more than the other on the spectrum
at first
I guessed that it would come back to the age old debate
nature vs nurture
Truthfully, just like introversion and extroversion
nature and nurture is not black and white
We know that now and I think we always have
It's a grey area because there's no way to say that someone's upbringing is completely due to their home lives
and there's no way to say that it's solely because of the environmental factors either
Let's say you get pushed around a few times as a kid
so you grow up to be quiet and secluded
because you were bullied as a child
or you grow up to be talkative and attention seeking
because you never got to be that as a child when you were being picked on
These are drastically different outcomes
So it can't be one surrounding that makes him or her an introvert
two different possible outcomes suggests that nurture is not a sole contributer
Well, according to Hans Eysenck
a psychologist from the 1960s
it's just got to do with our brain and its chemicals
You could be raised this way or that way
but as long as you've got your brain you will be who you are despite nature and nurture
In 1999 scientists measured the blood flow of introverts and extroverts
and found that introverts had more blood flow in their frontal lobes and interior thalamus
These sections of the brain are the parts that take care of remembering things
planning events
and solving problems
At the same time extroverts had more blood flow in brain areas
interior cingulate gyrus, the temporal lobes and the posterior thalamus
that had more to do with sensory
in this case, specifically for socializing
This may be why extroverts enjoy people's company
Since their brains are happiest when their senses are being stimulated
Carl Jeung suggests that this is why extroverts are more outwards and introverts are more inwards
over decades of research for the two personality types
most scientists have come to the conclusion
that it has a lot to do with dopamine in the brain
It is suggested that extroverts are less sensitive to dopamine
so they need a lot of stimulation to get enough of it
This has something to do with the amount of blood flow to certain sections of our brains
A 2012 study by Randy Buckener at Harvard University
found that introverts have thicker grey matter in their pre frontal cortex
linked to thinking and decision making
than extroverts did
He says that this is probably why an introvert can thoroughly consider outcomes of a decision
while an extrovert may make one and act upon it quicker
Now, if you're asking why some people have more blood flow in their frontal lobes
than their posterior thalamus
I couldn't tell you
I don't think there's enough research that's been done on the biology of the human being
let alone the human brain
to explain why we are built the way we are
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