Biological approaches suggest that genetics are responsible for personality. Research on heritability suggests that there is a link between genetics and personality traits. One of the best known biological theorists was Hans Eysenck, who linked aspects of personality to biological processes. For example, Eysenck argued that introverts had high cortical arousal, leading them to avoid stimulation. On the other hand, Eysenck believed extroverts had low cortical arousal, causing them to seek out stimulating experiences. Behavioral Theories
Behavioral theories suggest that personality is a result of interaction between the individual and the environment. Behavioral theorists study observable and measurable behaviors, rejecting theories that take internal thoughts and feelings into account. Behavioral theorists include B. F. Skinner and Albert Bandura. Psychodynamic Theories
Psychodynamic theories of personality are heavily influenced by the work of Sigmund Freud, and emphasize the influence of the unconscious mind and childhood experiences on personality. Psychodynamic theories include Sigmund Freud’s psychosexual stage theory and Erik Erikson’s stages of psychosocial development. Freud believed the three components of personality were the id, the ego, and the superego. The id is responsible for all needs and urges, while the superego for ideals and moral. The ego moderates between the demands of the id, the superego, and reality. Erikson believed that personality progressed through a series of stages, with certain conflicts arising at each stage. Success in any stage depended upon successfully overcoming these conflicts. Humanist Theories
Humanist theories emphasize the importance of free will and individual experience in the development of personality. Humanist theorists emphasized the concept of self-actualization, which is an innate need for personal growth that motivates behavior. Humanist theorists include Carl Rogers and Abraham Maslow. Trait Theories
The trait theory approach is one of the largest areas within personality psychology. According to this theory, personality is made up of a number of broad traits. A trait is basically a relatively stable characteristic that causes an individual to behave in certain ways. Some of the best known trait theories include Eysenck's three-dimension theory and the five factor theory of personality.