1. Introduction The present study is a comprehensive study of Qais ibn Amer, the main character of Layla and Majnoon of Nezami who, due to his unusual and irrational behaviors, led us to investigate his character with the help of personality theory of Raymond Cattle. This theory tries to describe the traits of a person that guide his behavior. “, Perhaps the most distinctive feature of the theory of traits is its emphasis on the traits that make up a person's personality”, . “, The theory of traits emphasizes that the personality of each person can be described according to his traits”,(Shojaei, 2010, p. 130). CATTELL considered the adjective as a psychological structure that is inferred from observing a specific human behavior and is responsible for the order and continuity of this behavior”,(Shamloo, 2003, p. 174). According to the above explanations, it should be said that “, the main axis of CATTELL's theory is the distinction that is made between two types of formal traits and basic or deep traits. Formal attributes are obvious and superficial and their duration is very short, and deep attributes are the source of formal attributes and the real causes of human behavior. These traits are enduring and are more important to CATTELL and they are in two categories: natural traits that are inherited and environmental traits that are obtained through learning and education and are the result of the environment”,(Karimi, 2005, p. 150-151). “, CATTELL divides traits into three categories based on how they manifest themselves as dynamic traits, traits that move a person toward a goal,ability traits, traits that show a person's talent, ability and ability to achieve a goal,and mood traits, traits that show characteristics such as energy, emotional response, speed of reaction and speed and motivational strength”,(Shamloo, 2003, p. 74). He considers human reactions to be due to two deep and dynamic attributes, which play a motivating role. 2. Methodology This research has been done by analytical-descriptive method. In this way, we have first studied the basics of CATTELL's theory from books related to the subject of research, then we have extracted the evidence of each of the main topics from Layla and Majnoon and we have examined each of them in detail. Finally, with a logical conclusion, we psychologically analyzed the personality of Qais ibn Amer for the audience. 3. Discussion The science of psychology helps us to better understand people's personalities, and this is very effective in improving the emotional relationships between different people in various fiction books. One of these people is Qais ibn Amer, the character of Layla and Majnoon of Nezami who has certain moral characteristics. To advance this, we used CATTELL's theory. By studying the story of Layla and Majnoon and using the above theory, we found Majnoon as a quiet and withdrawn person who does not show any sign of being social throughout the story. He was an anti-social person who, from an early age to a time when he was studying at school, became attached to Lily, which provided more space for Majnoon to withdraw from society. Also, according to the content of the story and the study of Majnoon's character, we found that the components making Majnoon an intelligent human being do not exist during the story, and this is mostly due to the love that gripped him at the very beginning of his intellectual maturity. He has completely unnatural reactions to behaviors and issues and problems. An example of this trait is found in Majnoon's character when his father argues with Layla about his love and starts advising Majnoon about it, but Majnoon forgets his father's words in an unusual behavior, this forgetfulness in such for a short time, it seems abnormal and indicates a disorder in majnoon intelligence. In most cases, he cannot control his emotions in terms of stability and excitement, and cries when he hears the slightest news. The character we are studying is a domineering person, and not only he does not have any objections to those who have dominated him, but also the person himself strengthens his ability in him, and this factor causes the person to give up the effort. Majnoon is also morally carefree. This carelessness is more related to social issues and customs, because love has dominated him in such a way that he completely withdraws from the surrounding events and is careless about them, but he is expedient towards a human being and his actions are more based on benevolence and he does it out of charity. An example of this type of behavior can be seen in freeing a deer from the hunter. Majnoon, seeing a rope around the neck of the hunter, takes pity on him and buys the deer from the hunter in front of his horse out of benevolence and charity. In terms of personality, Majnoon has an arrogant personality that insists on his affairs and desires, in which he not only is not afraid of anyone, but also acts very boldly and courageously. A clear example of this can be seen in the story when Majnoon's father takes her to the Kaaba's house so that he may give up Layla’, s love, but Majnoon stubbornly asks God not only to take Layla’, s love away from him for the rest of his life, but to take it from him and add it to Layla’, s life. In addition to the above, it should be said that Majnoon does not have a skeptical personality, but his behavior indicates a gullible human being who easily believes in the behavior of others and stands by these beliefs. While being gullible, he is very frank and openly declares his desire, and in this regard, he is not afraid of anyone, which shows that he is fearless, and in most issues, he is not afraid of dangers and problems, and with open arms they are welcomed. However, he relies more on others in his actions and promotes his behavior and actions by relying on others. Behaviorally, he has a very disturbed and anxious personality, and examples of this behavior are evident throughout the story. A person who exhibits disturbed behavior does not have a patient personality, and most of his reactions are of the unpleasant type, which eventually leads to hasty and far-fetched behaviors. It should also be noted that Majnoon is a fearful and worried person, and his fears and worries in life are more related to the love he has been caught in since school, and this has caused him to run away from the facts and fantasize more than his companion in a way that he walks around the animals and talks to them. 4. Conclusion Based on the above evidence, it can be said that Qais ibn Amer has many abnormal traits that take his behaviors away from positive traits and normal behavior and lead him to behaviors that are due to the depth of his emotions and these factors. It has caused the traits that can motivate him to advance to the goals not to be placed in the personality of this person enough and as a result he cannot act to get Layla himself and he is dependent on others to do so. Therefore, it can be said that this factor has caused the ability traits in this person to be completely weakened and open the way for mood traits leading to behaviors such as emotionality and unhappiness, and fear and worry in life and even anxiety and distress created in him and chain-linked these actions and behaviors as the result of the same acquired motivations that environmental conditions have caused it. Therefore, it can be noted that the frequency of negative and unusual actions of Qais is very high and leads him from an ordinary human being to a person with low intellect, which by analyzing and examining those behaviors based on CATTELL theory, we see that Qais ibn Amer has a personality which was with dementia that this was inherently institutionalized in his behavior.