Am I and EXTROVERT or an INTROVERT?

I regain energy when with friends, because I want to have fun, I don't want to be the party crasher. I think that INTROVERTS have it easier because they don't have to worry about there friends, or having friends.I think the world would be a happy place if everyone was an EXTROVERT, and if everyone was an INTROVERT, then the world would be an isolated, and boring place.So I think that I'm an INBETWEENERT, because I love hanging with friends and going to parties and stuff...... but, I also love to just chill by myself and play video games or read a book. I prefer to have friends that are EXTROVERTS, because they know how to have fun. EXTROVERTS are the leaders, INTROVERTS are better writers. EXTROVERTS are better neighbors because they can help you out, and are friendly. And I think INTROVERTS are the better teachers, because they are.... usually smarter.I think all this stuff does matter because its physiology... which is a real science.