The major modern trait and type theories of Gordon Allport, Raymond Cattell, Hans Eysenck and the Big Five vary in their approach and methods in their attempts to understand personality, yet all share the belief that personality can be understood and individual's behaviour could be explained and described by the use of types and traits. The trait and type personality psychologists used three methods in identifying important traits and types; the lexical approach, meaning the more important a word is the more often it will appear in lang

Most researchers agree with Eysencks classification and definition of dimension (1) Introversion/Extroversion and dimension (4)Neuroticism/Emotionality. Dimension (2) Agreeableness, as classified by Norman, Borgatta, Digman, Costa and McCrae, is generally supported {M, 1990 #31, (Digman, 1990). Dimension (3) Conscientiousness as classified by Norman, Goldberg and McCrae is also a generally accepted classification. Dimension (5) has been classified as Intellect by Digman and Takemoto-Chock, Goldberg, intelligence by Borgatta and Openness to experience by Costa and McCrae and this dimensions classification is the most controversial of the five factors(Digman, 1990).

Central traits describe the characteristics of a person which are noticeable in the person's interactions in their daily life and have less influence or control over an individual's behavior than a cardinal trait. Central traits control behaviour in different situations, however the control is not generalised in all aspects of a person's life (Liebert&Spiegler, 1990; Monte, 1999; Pervin&John, 2001)

Cattell labeled traits that describe behaviour, are easily observable and have origin in source traits source as surface traits. Cattell believed that; some source traits are hereditary and others are acquired through learning/experiences, that one source trait can influences a number of surface traits and surface traits result form the interactions of source traits (Liebert&Spiegler, 1990). He also believed each individual has unique traits and common source traits, which have varying degrees of influence. Cattell distinguished between ability, temperamental traits and dynamic traits, the most significant aspects personality. He defined ability traits as skills that enable individuals to function effectively, temperamental skills as relating to emotional functioning and dynamic traits as skills related to motivation {Phares, 1997}.

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According Allport, Raymond Cattell, Costa McCrae, Questionnaire Carver, , Allport Odbert, Eysenck Five, Cloninger Cloninger, Mathews Deary, Psychotism Carver, liebert&spiegler 1990, source traits, goldberg 1993, ryckman 2000, monte 1999, surface traits, ed ed, carver 1998, pervin&john 2001, trait type, 16 personality factor, five factor model, source traits source, norman borgatta digman, ed ed york,