What makes someone an Introvert? Is it the environment or genes that lead to introversion? Is someone born an introvert or adopts these habits by choice? You may confuse about this. Introverts and extroverts are two extremely different personalities with different behavioural traits.
In this article, we will discuss whether introversion can be inherited and about the genetic basis of introversion in detail that how genes can affect your personality.

Genetic Basis of Introversion:

The genetic basis of introversion is a topic that link with biochemistry. Research has proved that introversion is an inherited trait, and most of the introverted preferences are related to genetics. The human brain contains almost 60 neurotransmitters. These chemicals control the workings of the brain. Nearly each of us has the same chemicals, but there is a slight variation in the recipe of how we express them. Our genes determine our personality and many traits, like introversion and extroversion.

Response to Dopamine:

One of the most important neurotransmitters is dopamine. The brains of introverts are far less driven by dopamine than those of extroverts. Dopamine sensitivity is an example of neurotransmitters in action. The dopamine sensitivity determine by DNA. Introverts have more sensitiveness to this alertness chemical than extroverts. In fact, Introverts respond to these alert chemicals in busy places, and that’s why they dislike them. Introverts like staying in places with a few people or stay alone. On the other hand, extroverts are less responsive to this alertness chemical and don’t get nervous in busy places. Extroverts are comfortable in all places and don’t feel pressure. Introverts don’t require high levels of stimulation, and that’s why they prefer solidarity. Additionally, extroverts demand a high level of stimulation therefore, they search for outward activities.

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According to a study conducted in 2005 at the University of Amsterdam, they discovered in groups of volunteer students introverts and extroverts. These students could gamble, after some brain activities. In the brains of extroverts there were more activities in the amygdala (the part of the brain that generates emotions) and the nucleus accumbens (the part of the brain that releases dopamine). This study showed that extroverts’ brains respond more quickly to such situations than introverts.

Maybe Dopamine will be enough to convince you that being introverted is inborn. Some tests were converted that showed that introverts were more interested in any new flowers than human faces. A group of people were gathered and were shown some images with new faces and some with new flowers looking for a certain reaction called P300 (P300 because it appears in 300 milliseconds of exposure to something). This unconscious reaction showed that extroverts had more P300 levels when watching a new face. Whereas introverts’ P300 levels were raised when exposed to new flowers.

Test your introverted friends and ask them if they love their gardens more than you! Wait, it is just a single test. Let’s see other factors too.

Levels of Acetylcholine:

Extroverts need more stimulation to feel the same pleasure as introverts. Extroverts can involve themselves in activities without taking a break. However, introverts have a lower pleasure threshold than extroverts. Introverts can feel the pressure only from a single “night out”.

Another neurotransmitter linked to the brain’s pleasure centre is Acetylcholine. However, acetylcholine responds differently. Acetylcholine gives us pleasure by looking inward. Introverts prefer the feedback from acetylcholine because dopamine can overwhelm them. Introverts have a greater sensitivity to acetylcholine as compared to extroverts. Extroverts barely feel the effects of acetylcholine.

Patterns of Blood Flow:

Patterns of blood flow differ between introverts and extroverts. I know you would be pondering How?

  • Introverts have greater blood flow in areas of the frontal lobe and anterior thalamus-areas that link to problem-solving, future planning, and thinking about fun things you can do alone.
  • The brains of extroverts have greater blood flow in the temporal lobes and posterior thalamus–areas that interpret thoughts related to the outside world.

To what extent does the environment have an effect on introversion?

Then can introversion be inherited? We can say that, according to research, we are born either introverted or extroverted. But can we say that the environment has no influence on our personality traits? Presumably, No! Our environment has a great influence on one’s personality. The way a person reacts to his surroundings is very critical.

Most of the behavioural traits are developed in the early years of a person’s life. Environmental factors like facing any kind of emotional trauma in early life or being pushed back from sharing one’s opinion lead a person to stay silent and isolated.

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No doubt, genetics has a role in making a person introverted with inherited introversion, but the role of the environment is something that we can’t neglect. A person’s brain thinks the way he/she moulds it. Therefore, we can’t say that introversion is merely dependent on genetics. The environment also has an effect on it.