Why do extroverts like action, and introverts like calm?
It has to do with two powerful chemicals — dopamine and acetylcholine, “jolt juices” that hugely impact our behavior, according to J. Allan Hobson, a professor of psychiatry at Harvard.
Dopamine gives immediate, intense zaps of happiness when its users act quickly, take risks, and seek novelty.
Acetylcholine also rewards us, but its effects are more subtle. It makes us feel relaxed, alert, and content.
We introverts are more sensitive to dopamine, so too much of it makes us overstimulated and anxious, according to Dr. Marti Olsen Laney, who writes about the differences between introverted and extroverted brains in her book, The Introvert Advantage.
Extroverts are less sensitive to dopamine, so they require more of it to feel its pleasant effects. The more extroverts talk, move, and seek new faces, the more their brains light up with dopamine’s happiness hits.
On the flip side, acetylcholine makes us introverts feel good when we study, concentrate, or use our minds in any way, but extroverts hardly register this jolt juice’s gentle happiness bump.
We use different “sides” of our nervous system.
We all have two sides to our nervous system — the sympathetic side, which triggers the fight, fright, or flight response, and the parasympathetic side, which puts us in rest and digest mode.
Think about the sympathetic side as hitting the gas pedal, and the parasympathetic side as slamming on the brakes.
When the sympathetic system is activated, a person’s body gears up for action. Adrenaline is released, glucose energizes muscles, and oxygen increases. Areas of the brain that control thinking are turned off, although dopamine increases alertness in the back of the brain.
In parasympathetic mode, muscles relax, energy is stored, and food is metabolized. Acetylcholine increases blood flow and alertness in the front of the brain.
Of course, both extroverts and introverts use both sides at different times. But which side do introverts prefer? You’ve probably already guessed: the parasympathetic side, according to Dr. Laney.
We use different brain pathways.
Ever wonder why, as an introvert, you take longer to process things, or why you “overthink”?
It has to do with us introverts processing stimuli differently.
When stimulation enters an extrovert’s brain, the pathway to process it is much shorter. It travels through areas of the brain where taste, touch, visual, and auditory sensory processing take place.