Is there a physiological difference between introverts and extroverts?
An introvert is defined as ‘the tendency to direct one’s concern and attention towards one’s own life, thoughts, feelings and interests.’ A lot of the time we see introversion as something of a social curse. Extroverts are highly revered for their confidence and ways of dealing with people, but introversion is still a valuable trait to have.
Although the above definition is the official medical definition, it is not easy to boil introversion and extroversion down to a certain set of genes and brain chemistry. However, there are a lot of scientific studies that show how the brains work differently in both introverts and extroverts.
Here’s what we know:
Introverts tend to use a different neurotransmitter: acetylcholine
A study in 2005 found that extroverts had much stronger dopamine reactions in situations such as gambling and going out at night. They became chattier, more enthusiastic, and generally more stimulated. Introverts in the same situation closed up a bit more and seemed to feel overwhelmed.
The brain of an introvert tends to use acetylcholine, which makes us feel good when we turn inwards and powers our ability to think deeply and focus for long periods of time. This makes introverts much happier when they are in calmer environments and not having to react to external stimuli.
The difference between introverts and extroverts in terms of the nervous system
Acetylcholine is linked with a parasympathetic part of the nervous system. This part of the nervous system leads us to withdraw from our environment and begin to conserve our overall energy, ready to contemplate and almost ‘hibernate.’ This is the part of the brain that introverts tend to favour.
Extroverts tend to favour the opposite side, the part that is responsible for the ‘flight or fight’ phenomenon. This part of the brain becomes super alert and focused and thinking is reduced so that we become prepared to make snap decisions.
You were born an introvert or an extrovert
According to a 1999 study, introverts have a higher blood flow, and this can give them greater sensitivity to loud sounds and over stimulation. So, the chances are you were born into your introversion rather than developing it later on.
It’s not all about biology, though. The human brain has a remarkable amount of willpower, and the ability to change how it reacts in the world and how it doesn’t. Just because you were born as an introvert does not mean that you cannot become social. You are perfectly capable of changing how you react to your environment, as well as enjoying the little quirks of your introverted tendencies.