The branch of science that analyzes and breaks down the human mind and why people act the way they do is called psychology. Ever since the Egyptians, Greece and Persian eras of human history, psychology was there. And as human kind advances, the way human behavior is being studied and analyze also advances and becomes more scientific methodological.

Professional researchers, shrinks or those who practice psychology are called nothing else but psychologists. Some of the issues that are under the scientific duty of psychologists are personality, behavior and interpersonal relationships. In short, psychologists are interested with how humans act and react towards others and circumstances.

In the different branches of psychology, one of the most popular is personality psychology. Most companies employ the use of personality psychology when determining if certain people should be hired by asking them to answer a series of character determining questions. As the name suggests, personality psychology is about understanding an individual's personality and how it is similar or different from others.

It should be noted that when a person is to be tested for personality psychology, there should be a complete logical picture of that person first before coming up with results. The results of a person's personality tests should then be compared to people who are in the same conditions, scenarios or environment as he or she is. Studies on the similar traits among the subjects are then made.

A personality psychology theory that has claimed to be the most comprehensive study of human personality is called the Big 5 personality traits. Said to be the terms that define every aspect of human personality are neuroticism, openness, extroversion, agreeableness and conscientiousness. There will be instances that a person is in the extreme side of particular traits, maybe he or she is extremely neurotic and at the same time is in the opposite spectrum when it comes to being agreeable.

To further understand this highly regarded and held theory, we must take a look at each personality trait. People who show a lot of appreciation for art, imagination and adventure are most likely high in openness, while enthusiastic people and YES people are inclined to having extroversion traits. Conscientiousness in a person can be defined by the way he or she meticulously perform a task, and agreeableness is a person's tendency to be accommodating and pleasant during a situation.

Last but not the least is neuroticism, which is a personality trait that has the characteristics of anxiety, and emotional instability. As you can see, coming up with a way to define human personality is the first step in being able to study and eventually predict human personality. You may start to see how psychology is such a huge topic, as this one theory is simply a theory in a branch of personality psychology.

If you're asking why or where psychology is applied, the answer is simply a lot of different fields and industry. Humanity has spent years and years studying, analyzing and predicting human mind and soul. Criminal activities and even medical issues on mental health are just two examples of practical psychology applications.

Almost all and any fields out in the world today that uses human beings need psychology. For it is involved in better understanding the way the human mind functions. This is the reason why the workplace, big organizations, the media and even sports uses psychology.