The Science of Being an Introvert

I've read a few, OK, books on the subject, but I don't know which to recommend. I was originally inspired to read further on this after reading Carl King's article: 10 Myths About Introverts. None of these books are perfect, however, The Introvert Advantage, by Marti Olsen Laney, Psy.D. was one that really opened my eyes to the neurological and genetic differences between introverts and extroverts. This will be a partial review of the physical science in it and my own conjecture based on personal experience and education.

In the book, she references Matt Ridley's Genome: the Autobiography of a Species in 23 Chapter. Specifically, research by Dean Hammer (1994) on the D4DR gene directly influencing the responsiveness of dopamine in humans. In short: People with the longer gene are less responsive to the dopamine neurotransmitter. This means that they need more social stimulation to feel "normal" or good. It also means that people with the shorter version are more sensitive to stimulus and get overloaded easily in social situations.

This is tied into research done by Dr. Debra Johnson (1999) on introverted people having increased activity in frontal lobe regions and differences in their fronto-striato-thalamic circuit: Introverts using different and more complex brain pathways than extroverts. This pathway is compared to the acetylcholine one described by Stephen Michael Kosslyn and Olivier Koenig in Wet Mind: the New Cognitive Neuroscience.

Essentially, the physical science boils down to an introverted person possessing this shorter D4DR gene and their brain adapting to its dopamine sensitivity. Instead of mainly using the extrovert's shorter, simpler dopamine pathway, the introvert relies heavily on the more complex acetylcholine route. Although, I don't really know how much of this is working hypothesis vs. proven fact. It, for the most part, makes a lot of sense.

I've also found the relationship in various research between acetylcholine and spatial memory, very interesting. Dr. Linda Kreger Silverman in Upside-down brilliance: the visual-spatial learner, shows a positive correlation of moderately to highly gifted children and introversion.

Regardless of actual intelligence, the introvert has a more complex path to get from A to B. While this really isn't more efficient for communications, it does mean that their thoughts have, well, more thought put into them. This results in a more consistent state of heightened self awareness. Introverts reading this might be shocked to learn that their extroverted counterparts don't have their inner narrator constantly predicating a lot of their casual speech and actions.

Lastly, social pressures are the biggest issues with introverts. They are constantly viewed as having something "wrong" with them or needing to be "fixed." While lots of books will give you advice on how to better fit in, I strongly disagree. As an introvert, you are the Spock to their Kirk. While they may call you a green blooded alien and criticize your over rationalizing, they'd still be stuck in the stone age without people like you. Many introverts are the scientists, artists, and dreamers who make the world worth living in.