There have been scientific studies done on why introverts behave differently than extroverts. A big part seems to have something to do with the brain. In this article, you will come across words like dopamine, acetylcholine and the parasympathetic nervous system. Let's dive straight in now.
1. THEIR BRAINS PROCESS NEUROTRANSMITTERS DIFFERENTLY
Your internal reward system — ruled by dopamine — is different from an extrovert’s. Both of you produce the same amounts of dopamine, but the brain’s reward center is more active in extroverts. They feel accomplished and happy in community settings and receive gratification from successful social interactions. Introverts, on the other hand, receive less satisfaction from social interactions — they get overwhelmed and want to look for the nearest quiet space.
Extroverts revel in dopamine, while introverted people take pleasure from another neurotransmitter — acetylcholine. This chemical causes you to turn inward for rewards. It helps you reflect and focus on individual tasks, which many introverts do through calming activities like reading or creating art.
2. THEY OVERTHINK BECAUSE OF BRAIN PATHWAYS
Scientists have suggested that when information enters an introvert’s brain, it travels a lengthier pathway than it would in an extrovert’s. Input travels along the long acetylcholine pathway, hitting up several areas — including Broca’s area, the left hippocampus and the frontal lobes. Broca’s area controls speech and articulation, while the hippocampus places memories in long-term storage.
Introverts take longer to make decisions and produce responses because they’re busy recalling old experiences. When information enters the long acetylcholine pathway, it undergoes a process of comparing and contrasting between past experiences. Your mind contains thousands of events, and this expanse overwhelms you with options. Because you have so many to pick from, you can spend a long time weighing all possibilities to get the preferred outcome.
3. THEY LEARN BY THINKING INSTEAD OF DOING
Extroverts are likely to prefer an experiential learning style, which means they want to be hands-on. They volunteer for projects, clubs and local initiatives, and they learn from communicating with others. Many extroverted people learn best by applying learned concepts to real-world situations.
Introverts prefer to retain knowledge through self-paced learning and analytical thinking. Overthinking can come into play here, but introverts’ long neural pathways also help them work through theories and ideas. Solo projects that forgo presentation or peer review allow introverts to express themselves without judgment and let their creativity reign. They prefer to brainstorm and consider all avenues before acting.
4. THE NERVOUS SYSTEM PLAYS A ROLE
Introverted peoples’ bodies may utilize the parasympathetic nervous system more than the sympathetic nervous system. The PSNS decreases heart rate and blood pressure, relaxes your muscles and metabolizes food. It’s like tucking in and going to sleep, or resting after a long day — activities introverts love.
The SNS controls the fight-or-flight mode humans feel when under stress or threat. It speeds up the heart rate and breathing, causes sweating and reduces the time needed to make decisions. These characteristics are what make extroverts so lively, optimistic and eager to accept new challenges.
5. BLOOD FLOWS DIFFERENTLY WITHIN THEIR BRAINS
In a 1999 study of 18 subjects, scientists discovered that introverted individuals experience higher rates of blood flow across their frontal lobes and anterior thalamus — areas associated with problem-solving and decision making. Extroverted people had more blood flow across the posterior thalamus and insula, which interpret sensory data.
Introverts favor contemplation over immediate action, while extroverts tend to be impulsive and willing to take risks. This study suggests that introversion and extroversion originate from biology rather than upbringing or environment. More research is needed to support this study, but it provides plenty of valuable insight in the meantime.
6. THEY ARE MORE SENSITIVE TO STIMULI
Introverts pay a lot of attention to the outside world, even if they’re not actively engaged in it. If you have a conversation with someone in a coffee shop, you aren’t just focusing on them. You’re thinking about the person across the room tapping their fingers, the waitress walking to a nearby table or someone slurping their drink. High-stimuli environments pose a problem for you because your brain goes in a hundred directions.
That’s why many introverts prefer low-stimuli situations. They’re less stressful on the mind and provide fewer distractions to analyze. Extroverts fare better in high-stimuli environments, while quiet areas make them anxious and lonely.