4 Things That Make the Introverted Brain Different from the Extroverted One

Published by
Kirstie Pursey

Research suggests there are key differences between the extroverted and introverted brain.

Have you ever wondered why introverts and extroverts are so different?

If you are an introvert, chances are that while you enjoy the company of others at times, you find too much social interaction tiring. I know I find socializing in large groups overwhelming and exhausting while the extroverts I know seem to thrive on it.

Why is this?

Well, research has suggested that there are 4 key ways that the introverted brain differs from the extroverted one.

1. The prefrontal cortex

The prefrontal cortex is the region of the brain that is linked to abstract thought and decision-making.

A study by Randy Buckner of Harvard University discovered that introverts tended to have larger, thicker gray matter in their prefrontal cortex while extroverts had less gray matter.

From this evidence, Buckner concluded that this might explain why introverts ponder things thoroughly before making a decision, while extroverts are able to live in the moment and take risks without fully thinking everything through.

2. Cerebral blood flow

Cerebral blood flow is an indicator of brain activity.

Debra Johnson, Ph.D., and John S. Wiebe, Ph.D., used positron emission tomography (PET) to measure cerebral blood flow in individuals rated on a personality test as quiet or gregarious.

The images the researchers obtained showed a difference between the quiet and outgoing participants. Introverts showed increased blood flow in the frontal lobes, the anterior thalamus and other structures associated with making plans and problem-solving.

Extroverts, however, displayed more activity in the posterior thalamus and posterior insula, which are regions of the brain associated with interpreting sensory data.

From these results, researchers concluded that introverts are more inward focused while more gregarious individuals crave external sensory stimulation.

3. The nervous system

We all have two sides to our nervous system. The parasympathetic side, which makes us conserve energy and withdraw from the outer environment and the sympathetic side, also known as the “full-throttle” or “fight, flight, or freeze” system.

According to Dr. Marti Olsen Laney in her book The Introvert Advantage: How to Thrive in an Extrovert World, both introverts and extroverts use both sides of their nervous systems at different times.

However, she suggests that extroverts tend to favor the sympathetic side, which makes them active, daring, and inquisitive. In addition, in this system, the brain becomes more alert and hyper-focused on its surroundings. This also leads to a reduction in thinking.

While extroverts thrive when they engage the sympathetic side, for introverts, it’s too much.

4. Dopamine

The final way in which the introverted brain is different is to do with a neurotransmitter found in the brain called dopamine. Dopamine plays a role in the brain’s pleasure and reward centers. It enables us to notice rewards and take action to move toward them.

This dopamine release also explains why introverts need to be alone to recharge while extroverts are energized by social interaction. The brains of introverts and extroverts reward different behavior. As introverts do not get the energizing reward of a dopamine release in social situations, they find interactions more tiring than their extroverted peers.

What this means for introverts

I find this research reassuring because as an introvert I have sometimes felt guilty that I dread big social occasions rather than looking forward to them. I felt there was something wrong with me –  that I was anti-social. Now I know that these traits are to do with my introverted brain and not something I can necessarily control. This makes me feel better about myself.

Being outgoing and sociable is not the only skill that is of value. Sometimes being thoughtful and introspective is just as important. As introverts, we should stop feeling inadequate and value the traits we do have. This way, we can play to our strengths.


  1. Randy Buckner https://www.hms.harvard.edu
  2. Scott Barry Kaufman https://blogs.scientificamerican.com
  3. Colin DeYoung https://www.ncbi.nlm.nih.gov
  4. Debra Johnson, Ph.D., and John S. Wiebe, Ph.D.http://ajp.psychiatryonline.org

View Comments

Published by
Kirstie Pursey