In a previous poorly written and confusing post, I tried to explain the correlation between the energy our brains use, habits, and self improvement. Every time we make a decision we use up some of the energy that we have available. Deciding what to eat for lunch, deciding/resisting the temptation to eat a cupcake at work, all take up energy and make us mentally tired. Some decisions use up way more energy than others. One way to reduce the amount of energy we use is to make habits. Habits end up existing as pre-made decisions. If you line up your clothes in you closet so that in the morning you just put on the next outfit, you won't use up any brain energy deciding what to wear. I had a friend who always ate the exact same thing for lunch and made it the night before. He never had to put out any effort into lunch either in the morning or at lunch time. We regain this energy through sleep, relaxing, and eating.
What does any of this have to do with extroverts and introverts? The current definition of an introvert is someone who re-energizes through being alone or with a small number of people in quiet situations. An extrovert replenishes their energy from being in public loud and active situations that involve a lot of people. I bet you can see where I am going with this?
Maybe the reason people recharge is because they are doing the thing that requires the least amount of effort. For the person who is used to coming home and going out with friends or stopping for happy hour on the way home being with people in a social environment takes almost no efforts. This allows them to rebuild their energy. It would take way more effort for them to say no to going out with their friends and staying in to read a book. The opposite for introverts.
The main reason I think there may be something to this idea is my own life. And as we all know science is powered by personal anecdotal evidence. In my life I have flipped multiple times between being extroverted and being introverted. I have had long periods of time where I would just stay at home and play video games and watch tv and times were I would go hang with friends almost every night.
Some circumstance in my life ususally precipitated these shifts. I moved or some event ocurred that I repsonded to by changing my behavoir for a long period of time until that became my new behavior.