Introversion and Extroversion Around the world, nowadays you can see various personalities, different attitudes, and behaviors. Therefore, the psychologists are making a lot of researches and studies about how the personalities affect the human thinking and behavior. People are being taught that everyone has distinguished personality. However, two types of opposite personalities that always make the psychologists deep in thought about them are introverted and extroverted personalities. The simplest definition of extroverted personality is describing a person who adjusts with people easily in social situations and events (1). Furthermore, extroverts gain energy from interaction with people every day (2). For instance, Adeson , an American inventor , had many drawbacks in his life particularly when he was a student. His teachers hated him and called him stupid. However, he did not give up. He became more extroverted. He studied a lot at home and invented many helpful inventions like the battery that power the cars. He is a good example of a successful extroverted inventor who lead the world by his importamt achievements (3). We all know Albert Einstein, a scientist, who developed the theory of relativity. In fact, he had an introverted personality. Despite his personality, he is considered the most influential physicist of the 20th century (1). On the other hand, an introverted personality does not