Human resources have always been considered as the main axis for development in any organization. It is only the human resources who can help an organization move forward by being thoughtful and creative. The more important and sensitive an organization, the need for having skill ful staff. However, it is clear that not all individuals are similar in their characteristics, abilities and personality. As a result, some people may not be appropriate for certain jobs while some others are more likely to succeed in the same responsibilities. Although many variables are involved, it seems that in most cases the major variable playing a role in distinguishing individuals from each other is their personality. According to Holland (
1), job satisfaction is the result of the correspondence between one’s type of personality and his working environment. The more the two match, the more satisfied an individual feels. However, due to its diverse applications, Reber (
2) considers personality very resistant to definition. Reber claims that presenting a single unified definition for personality is impossible because each scholar and psychologist defines it differently based on the area in which they are using this concept. For instance, Allport (
3) listed 50 different definitions for the concept of personality. These definitions range in domain from one’s internal processes to observable behaviors resulting from one’s interaction with the environment (
4). In 1936, Allport and Odbert (
5) worked on the adjectives listed in English dictionaries. They identified more than 18,000 adjectives and tried to categorize them. Their study formed the framework for the lexicology of personality. Cattell (
6), working on the same adjectives, could reduce them to 4,500 adjectives which he categorized into 35 personality traits. Fiske (
7) could later reduce those 35 factors to 22 traits, very similar in structure to the Big Five personality traits we know today. These factors were repeated in other psychologists’ studies in the following years and became famous as the Big Five (
8). This, however, does not mean that all personality differences were reduced to five traits. Instead each factor is in fact one aspect of one’s personality which covers a wide range of adjectives and characteristics. In the early 1980s, Casta and McCrae (
9) developed a questionnaire to measure personality traits. They called it NEO, which covered only the three factors of neuroticism, extraversion, and openness. Later in 1985, they developed NEO PI-R or NEO Psychological Inventory, Revised to include the other two factors of agreeableness and conscientiousness. The NEO PI-R is a measure of normal personality, encompassing five meta-factors with six distinct facets for each factor, through the use of 240 five-point Likert scale items. One’s responses to these items are compared to those of other adults in order to make a description of their personality in terms of their thoughts, feelings, goals, and manner. Though it is not designed to measure mental disorders or problems, it can help understand what distinguishes an individual from others in terms of their thoughts, feelings, and interaction with others. The higher the score one obtains on a scale, the more the suggested description for each scale matches their characteristics. This is also true for low scores (
10).