Probably you have considered yourself or others to be introverts, and you probably have associated with it traits such as quiet, distant, timid, and so on. However, neuroscience has shown us that introversion can be understood mainly from the amount of social interaction a person needs rather than the quality of their social skills. 

What is the difference between an extrovert and an introvert, then?

Let's see how Jim, an introvert, and Katie, an extrovert, behave and feel when they both go to the same party. 

Jim arrives at 8 pm, he was looking forward to seeing his friends and meeting new people. He approaches two of his work friends and starts chatting. He feels joy while interacting, there is an internal increase of dopamine, making him still feel motivated to continue interacting and enjoying the evening. After three more interactions, he feels satisfied, his brain has released enough dopamine and now is depleted. He is ready to leave at 10 pm, but he feels guilty for leaving so early, so he stays longer. By 11 pm Jim feels tired, and not willing to keep the same effort to socialise, he retreats and becomes more quiet. He considers it's been enough for today and makes a move to go home, making numerous excuses to justify wanting to leave so early. 

On the other hand, Katie arrives at 8pm, she was looking forward to seeing her friends and meet new people. She approaches two of her work friends and starts chatting. She feels joy while interacting, there is an internal increase of dopamine, making her feel motivated to continue interacting and enjoying the evening. After three more interactions, she does not feel satisfied, her brain has not released enough dopamine and needs to continue engaging socially to feel fulfilled. By 10 pm she is not ready to leave, she can stay longer as she still feels energised. By 11 pm she says bye to Jim and decides to stay. At 1 am she felt tired and fulfilled, ready to go home without feeling she missed out on socialising as she noticed most people were also leaving.

As you can see, Jim and Katie are both sociable and willing to engage in social events, finding enjoyment in them. However, the amount of social interactions they need is different, and this is due to not only their personalities but also their physiological differences. Jim seems to release a greater amount of dopamine when socialising, making him feel fulfilled quicker. On the other hand, Katie seems to gain a smaller amount of dopamine when interacting socially, making her wanting to seek more interactions for a longer period. 

This difference does not mean that Katie is more fun than Jim, or that Jim is antisocial and unconsiderate. They just operate differently for different reasons, they both have adapted to their social world in a way that better works for their personalities and physiology. 

However, it is important for you to know that we are not stuck into one extreme or the other, the reality is that we can be an in between, or feel more introverted or extroverted in different stages of our lives. These qualities can change and are adaptations that are the product of the interaction between our personalities and the social context we are immersed in during an extended period of time. 

This might seem a bit technical to be a practical piece of information, nevertheless, it is important that you listen to the internal signs that your body is manifesting. Everyone is different, we live and engage with the world in different ways and they are all valid. There is no need to perform in ways that feel more socially acceptable if they go against who we are.