5 Steps to a 5 AP Psychology, 2010-2011 Edition (52 page)

Key Ideas

Biological/evolutionary theories of personality

Psychoanalytic/psychodynamic theories of personality

Humanistic theories of personality

Behavioral theory—operant conditioning

Cognitive theories of personality

Trait theories of personality

Assessment techniques

Self-concept and self-esteem

To what extent is our personality determined by our heredity? Thousands of years ago, Greek physician and philosopher Hippocrates attributed personality to our biology. About 500 years later, Greek physician Galen claimed that a person’s temperament depends on relative quantities of four humors, or fluids, in the body—blood and cheerfulness, phlegm and calmness, black bile and depression, yellow bile and irritability. In about 1800, seeking to relate behavior to observable aspects of physical makeup, Gall and Spurzheim related bumps and depressions on the skull to personality traits in their discredited theory of phrenology, and a half century ago, psychologist and physician William Sheldon related physique to temperament. According to his somatotype theory (which can be classified as a biological type theory), the soft, spherical endomorph is likely to be sociable and affectionate; the hard, muscular mesomorph is likely to be aggressive and courageous; and the linear and fragile ectomorph is likely to be restrained and happy to be alone.

Currently,
temperament
, an infant’s natural disposition to show a particular mood at a particular intensity for a specific period, is generally considered the hereditary component of personality. According to Jerome Kagan, temperament includes sensitivity, activity levels, prevailing mood, irritability, and adaptability. Twin and adoption studies have been revealing the extent to which family resemblance of behavioral traits results from shared genes and the extent to which the resemblance results from shared environments. Heritability estimates suggest a moderate role of genetic influences (about 50%) in explaining individual differences in emotional stability. This indicates that both heredity and environment have about equal roles in determining at least some of our personality characteristics. New behavioral genetics methods may provide better data in the near future.

David Buss, an evolutionary psychologist, attributes the universality of basic personality traits to natural selection because traits such as extraversion and agreeableness ensure physical survival and reproduction of the species.

Sigmund Freud

Although Sigmund Freud was a Viennese physician who practiced as a neurologist in the late 1800s and early 1900s, he was unable to account for personality in terms of anatomy. He and other psychoanalysts believed that people have an inborn nature that shapes personality. Practicing in the Victorian era (known for self-control of physical drives), and as a result of treating patients suffering from mental disorders, Freud thought that sexual conflicts hidden from awareness caused many of the problems. He developed a psychoanalytic theory to explain human behavior based on his case studies and self-analysis. Freud compared personality to an energy system, with instinctual drives generating psychic energy to power the mind and press for release directly as sexual activity or aggression, or indirectly. Freud described three levels of the mind: the conscious, preconscious, and unconscious. The
conscious
includes everything of which we are aware at a particular moment. Just below the level of conscious awareness, the
preconscious
contains thoughts, memories,
feelings, and images that we can easily recall. Generally inaccessible to our conscious, the largest part of the mind, the
unconscious
, teems with wishes, impulses, memories, and feelings. Threatening thoughts or feelings can be repressed or pushed into the unconscious. Glimpses of the unconscious are revealed through slips of the tongue and dreams.

Freud’s Personality Systems

Freud also described three major systems of personality: the id, the ego, and the superego. We are born with the unconscious
id
, which consists of everything psychological that is inherited, and psychic energy that powers all three systems. The id demands immediate gratification of its desires with driving forces, and is guided by the
pleasure principle
, which reduces tension whenever it rises. The id is driven by instincts to avoid pain and obtain pleasure, and is totally irrational and self-centered. The partly conscious and partly unconscious
ego
mediates between our instinctual needs and the conditions of the surrounding environment in order to maintain our life and see that our species lives on. The ego obeys the
reality principle
to prevent the discharge of tension, sometimes using restraining forces, until a need can be satisfied appropriately. The last system of our personality to develop is the partly conscious and partly unconscious
superego
, which is composed of the conscience and the ego-ideal. The conscience punishes us by making us feel guilty, and the ego-ideal rewards us by making us feel proud of ourselves. The ego must check both the id and the superego to govern the personality, as well as engage with the external world. Cartoons sometimes depict a character (ego) with a devil on one shoulder making demands that the character do something impulsive or primitive (id), and with an angel on the other shoulder telling the character to do the right or noble thing (superego); the character decides what to do.