What Science Has To Say About Introversion

We all breathe the same air, trod the same streets and all put our pants on one leg at a time, however, there is a clear distinction between our personality and perception. Why is that? Is it something in our DNA, or is it simply due to how we were raised? Let's see what science has to say about being an introvert, and how and why we differ from our counterparts.

Where it all began

The word “introvert”, along with “extrovert” had to have come from somewhere right? So who came up with this whole concept in the first place?

Well, it was back in 1921 when Swiss psychoanalyst Carl Jung decided to explore the concepts of introversion and extroversion that the terms became popularized. 

In a nutshell, introverts, according to Jung, tend to find happiness in solitude, and gain energy from inward thinking. Extroverts on the other hand gain their energy from outward interaction, and worldly stimuli, such as social encounters. 

Introversion and shyness

When many people hear the word “introvert” they automatically equate it to shyness so much so that the words have been used interchangeably. However, according to Psychologist Stephen Briggs, “shyness as a construct is conceptually distinct from the wellknown dimensions of introversion (-extraversion) and neuroticism.” 

In simpler terms, introvert ≠ shyness. Introverts may appear shy, but shyness entails fear and discomfort in social situations. Despite the need to recharge internally, introverts are just as comfortable as any other participant in the interaction even if they don’t say so with as many words. With that being said, one may be introverted and be shy at the same time. 

Introversion and extroversion lie at the core of many human personality theories. From there, Jung explained that no one is purely introverted or extroverted. Instead, we tend towards one end of the spectrum or the other, and in the middle of that spectrum lies the ambiverts. 

Nature versus Nurture

How does one become an introvert? Were we born this way, or does it have something to do with our upbringing or environment?


In the 1960s, psychologist Hans Eysenck published his theory about introversion and extroversion, and what he believed was that everyone has a different level of arousal. No, not the sexual type, but instead in the physiological sense where our bodies and minds are prepared to respond to stimuli. To him, it was all biological, as extroverts have a lower basic rate of arousal, thus the need to compensate through outward interaction. Introverts, on the other hand, have a ‘normal’ rate of arousal, thus their craving for social interaction is not as high as that of extroverts. As a result, introverts are easily overstimulated and will find pleasure in what others might see as mundane, or otherwise not stimulating enough. 

Research has also suggested that dopamine plays a huge role in whether one is scientifically introverted or extroverted. Dopamine is a type of neurotransmitter responsible for controlling things like movement, motivation, and more familiarly, pleasure. It is the “feel-good” neurotransmitter that is responsible for certain behaviors and mannerisms. You will notice the similarities between this and Eysenck’s theory, as introverts are more sensitive to dopamine, and are easily overstimulated. 

 In 2005, a study was conducted using brain scanners, personality tests, genetic swabs, and gambling as the dopamine trigger. When the gambles were successful, the brain scanner showed that the extroverts experienced a stronger response to the reward. Additionally, the genetic profiles of the participants included a specific gene that increases the response of dopamine in the body.


Ok, so that was nature, but what about nurture? Does this play any role in introversion?

Well, in one study of nearly 500 parents and children, it was determined that the family environment can influence the development of personality types. More specifically, parents with “logical” parenting styles tend to have children with more extroverted personalities. 

There are limitations to these types of studies and many theories suggest that genetics play a larger role in determining whether you are an introvert or an extrovert.

Types of introverts

Remember, Jung said that there is no pure introvert or extrovert, and we all fall at some part of the spectrum. Research psychologists John Creek, Jennifer Grimes, and Julie Norem argue there are four domains of introversion, and many of us are a mixture of these domains. 

These domains are:

  1. Social Introversion- Social introverts have a preference for solitude. However, there is no anxiousness behind this, and they will enjoy smaller group settings.
  2. Thinking Introversion- Thinking introverts are introspective. They are more creative and tend to get lost in their thoughts, even in the middle of conversations.
  3. Anxious Introversion- Anxious introverts avoid social interaction on purpose and prefer not to be in the spotlight. This type of introvert may appear to be rude, distant, or avoidant, but it is simply a defense mechanism. 
  4. Inhibited Introversion- Inhibited introverts, sometimes referred to as restrained introverts, prefer to think before they speak or act. They are careful decision-makers and are very strategic or methodical. They have their guards up but warm up to others in time once they can predict or control the situation. 

Finding your own path

Humans are curious creatures as we all know. We want to reach the deepest depths of the ocean and go farther and farther into space with each launch. We want to explore everything there is to know about everything including the human mind and what makes us tick. Years of research has gone into understanding what makes us different, and sometimes that effort to learn everything has created these boxes that we are somewhat forced into. 

The science is the science, and yet science changes and evolves. Not too long ago, the Earth was flat and the cure for some mental illnesses were lobotomies and shock therapy. What this means is that you should bear all these things in mind, but don’t forget to find your own path. The definitions exist, the stereotypes exist, but there is only one you. Perfectly made, yet still a work in progress.

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