Another difference between introverts and extroverts has to do with our nervous systems. Everyone’s nervous system has two “sides” — the sympathetic side, which triggers the “fight, fright, or flight” response, and the parasympathetic side, which is responsible for “rest and digest” mode.
In other words, the sympathetic side is like hitting the gas pedal, while the parasympathetic side is like slamming on the brakes.
When your sympathetic system is activated, your body gears up for action. Adrenaline is released, glucose energizes muscles, and oxygen increases. Areas of your brain that control careful, measured thinking are turned off, although dopamine increases alertness in the back of your brain.
On the other hand, when you engage the parasympathetic side, your muscles relax, energy is stored like a squirrel preparing for winter, and food is metabolized. Acetylcholine increases alertness and blood flow to the front of your brain.
To be clear, extroverts and introverts use both sides of their nervous systems at different times. But which side do we introverts generally prefer? You’ve probably already guessed: According to Dr. Laney, we prefer the parasympathetic side, which slows and calms us.
Ever wonder why, as an introvert, you are prone to overthinking? It may have to do with how we process stimuli differently than extroverts.
When information from the outside world — like someone’s voice or images on a computer screen — enters an extrovert’s brain, it travels a shorter pathway, Laney theorizes. It passes through “quick response” areas of the brain where taste, touch, sight, and sound are processed.
If Laney’s theory is correct, this means introverts process information more thoroughly than extroverts do
. No wonder it can take us longer to put our thoughts into words, react, or make decisions!
This is a definition of extraversion/introversion.
Extroverts make fast decisions but they can be imprecise. Introverts make slow decisions but they are usually precise.
This also explains why there are no ambiverts, since we are either in the extroverted mode or in the introverted mode.
I also think everybody has a preferred side.