B. Personality Determinants - Motivation Theory
1. An early argument centered on whether or not personality was the result of heredity or of environment.
a. Personality appears to be a result of both influences.
b. Today, we recognize a third factor—the situation.
2. Heredity
a. Heredity refers to those factors that were determined at conception.
b. The heredity approach argues that the ultimate explanation of an individual’s personality is the molecular structure of the genes, located in the chromosomes.
c. Three different streams of research lend some credibility to the heredity argument:
i. The genetic underpinnings of human behavior and temperament among young children. Evidence demonstrates that traits such as shyness, fear, and distress are most likely caused by inherited genetic characteristics.
ii. 100 sets of identical twins who were separated at birth were studied. Genetics accounts for about 50 percent of the variation in personality differences and over 30 percent of occupational and leisure interest variation.
iii. Individual job satisfaction is remarkably stable over time. This indicates that satisfaction is determined by something inherent in the person rather than by external environmental factors.
d. Personality characteristics are not completely dictated by heredity. If they were,
they would be fixed at birth and no amount of experience could alter them.
3. Environment
a. Factors that exert pressures on our personality formation:
i. The culture in which we are raised
ii. Early conditioning
iii. Norms among our family
iv. Friends and social groups
b. The environment we have exposed to plays a substantial role in shaping our personalities.
c. Culture establishes the norms, attitudes, and values passed from one generation to the next and create consistencies over time.
d. The arguments for heredity or environment as the primary determinant of personality are both important.
e. Heredity sets the parameters or outer limits, but an individual’s full potential will be
determined by how well he or she adjusts to the demands and requirements of the
environment.
4. Situation
a. Influences the effects of heredity and environment on personality
b. The different demands of different situations call forth different aspects of one’s personality.
c. There is no classification scheme that tells the impact of various types of situations.
d. Situations seem to differ substantially in the constraints they impose on behavior.