Rethinking the Qualifications for Introverts and Extroverts

Currently, I am in stage one of my research for this project, which is the research through literature stage.  While in this stage, I have made several discoveries about the behavioral differences between social introverts and extroverts, including the fact that current social perceptions of these two types of people may be based on archaic definitions.  Most Americans define introverts and extroverts using a Jungian-type inventory (named after Freudian contemporary Carl Jung), meaning that they associate extroverts with being loud while associating introverts with being shy.  However, this type of identification method appears outdated, as most psychologists now define these two types of people depending on where they get their energy and motivation from, the options being themselves or other people.  Whereas most extroverts may generally be loud and most introverts may generally be shy, these qualities should serve moreso as associations with the personality than as the definitive guidelines for identification.  In general, extroverts require more external stimulation than introverts.  Extroverts need motivation from other people and often express their emotions while seeking stimulation; introverts, on the other hand, can be easily over-stimulated and may focus internally as they struggle with sensory overload if they focus too much on external stimuli.  Introverts feel the need to bottle up their motions so as to keep everything in order, focusing moreso on concepts and ideas than on people and things, which are the focus of extroverts.  While extroverts are usually relaxed and confident, actively looking to change the world and preferring commotion over peace, introverts are usually timid and reserved, simply looking to understand the world and preferring quiet so as to focus their energies.  Extroverts are more accessible for social interactions than introverts, but introverts, while sometimes taking interests in a smaller number of subjects when compared to extroverts, often have both the patience and the focus to think and work more deeply.  Although neither extroverts nor introverts possess extremely negative qualities, they can often misinterpret the others' actions in a negative manner.  Introverts, who prefer to stay reserved, may see extroverts as being shallow and pushy as they attempt to express themselves, while extroverts, who seek action and interaction, may view introverts as shallow and egocentric as they plan the best course of action, often requiring peace and quiet as they focus internally on the subject.
What drives these differences between introverts and extroverts?  What factors cause these two groups of people to respond differently to the same situation?  To begin with, as mentioned in previous posts, there are few pure introverts and/or pure extroverts.  Depending on the situation, an individual may act like an introvert or extrovert at different times.  However, most individuals do lean toward one end of the spectrum for the majority of situations.  Many researchers present evidence that imply that these behavioral differences may be due to genetics, or rather, the way that the brain functions.  As previously mentioned, some of these differences are due to disparities in the absolute thresholds for individuals, meaning that differing amounts/levels of stimuli are required to arouse individuals, and by effect, that differing amounts/levels of stimuli may eventually overwhelm them as well.  In addition, research has shown that introverts and extroverts use different areas of their brain when responding to situations.  In a 2005 study, researchers concluded that extroverts may respond more strongly to social challenges, taking risks, and adventures because two regions of their brains, the amygdala and the nucleus accumbens, exhibit stronger responses than those of introverts.  This suggests that extroverts may process surprise and reward differently than introverts, leading them to be more susceptible to taking risks.  In a 2012 study conducted by Randy Buckner of Harvard, Buckner found that larger, thicker gray matter is present in the prefrontal cortex, a region linked to abstract thought and decision-making, of introverts as opposed to extroverts.  He suggested that this may account for the reason why introverts may wait and ponder a situation while extroverts often prefer to take action and live in the moment.  Surprisingly enough, traces of introversion and extroversion are present even in babies.  Supposedly forty percent of babies are "behaviorally uninhibited," or extroverted, meaning that they react calmly to stimulation, while fifteen to twenty percent of infants qualify as having "extreme shyness," or being introverted, meaning that they thrash about and cry in reaction to stimulation.  After extensive research, it appears that the levels of activity of the neurotransmitters dopamine and serotonin, as well as the levels of activity of the amygdala, strongly influence the reactions of and behavioral differences between social introverts and extroverts.
I plan to continue in stage one of my research for this project for at least a few more weeks, although I may also, at the same time, begin stage two of research, that being research through surveys, polls, and interviews.  One of the next subjects that I will be researching in stage one will be the effect of environment on individuals, determining whether they will be introverts or extroverts.  For additional information and material on the subjects discussed in this post, which I will continue to elaborate on in further posts, please refer to the following websites, which helped me in my own research:

"Extraversion vs. Introversion"
"Life's Extremes: Outgoing vs. Shy"
"The Brain Of An Introvert Compared To That Of An Extrovert: Are They Really Different?"


 Works Cited:
Bushack, Lecia.  "The Brain Of An Introvert Compared To That Of An Extrovert: Are They Really Different?"  Medical Daily.  IBT Media Inc., 21 Aug. 2014.  Web.  7 Nov. 2014.
"Extraversion vs. Introversion."  ChangingMinds.org.  Changing Minds, n.d.  Web.  7 Nov. 2014.
Hadhazy, Adam.  "Life's Extremes: Outgoing vs. Shy"  LiveScience.  Purch, 25 Sept. 2011.  Web.  7 Nov. 2014.