Biological Factors
Although humans may not exhibit instinctive behavior, we are still ultimately a product of our biological makeup, our specific DNA pattern. Our individual DNA pattern is unique, unless we happen to be an identical twin, and it not only provides the basis for our learning and cognitive abilities, it also sets the conditions for certain aspects of our character. Perhaps the most salient of these characteristics is temperament , which can loosely be described as the emotional component of our personality. In addition to temperament, twin studies have shown that all aspects of personality appear to be significantly influenced by our genetic inheritance (Bouchard, 1994; Bouchard&McGue, 1990; Bouchard et al., 1990). Even such complex personality variables as well-being, traditionalism, and religiosity have been found to be highly influenced by our genetic make-up (Tellegen et al., 1988; Waller et al., 1990).
Sociobiologists and evolutionary psychologists also emphasize the role of genetics and adaptation over time. Sociobiologists consider how biological factors influence social behavior. For example, they would suggest that men are inclined to prefer multiple sexual partners because men are biologically capable of fathering many children, whereas women would be inclined to favor one successful and established partner, because a woman must physically invest a year or more in each child (a 9-month pregnancy followed by a period of nursing). Similarly, evolutionary psychologists consider how human behavior has been adaptive for our survival. Humans evolved from plant-eating primates, we are not well suited to defend ourselves against large, meat-eating predators. As a group, however, and using our intellect to fashion weapons from sticks and rocks, we were able to survive and flourish over time. Unfortunately, the same adaptive influences that guide the development of each healthy person can, under adverse conditions, lead to dysfunctional behaviors, and consequently, psychological disorders (Millon, 2004).
Discussion Question: Some research suggests that personality is largely determined by genetics. Do you see similarities in your personality as compared to your parents, grandparents, brothers, sisters, etc.? Do you think that your environment, things like your community, your friends, television, movies, the Internet, etc., are more influential than your biological inheritance from your parents?
Inherent Drives
Freud believed that we are motivated primarily by psychosexual impulses, and secondarily by our tendency toward aggression. Certainly it is necessary to procreate for the species to survive, and elements of aggression are necessary for us to get what we need and to protect ourselves. But this is a particularly dark and somewhat animalistic view of humanity. The humanistic psychologists Carl Rogers and Abraham Maslow believed in a positive view of people, they proposed that each of us contains an inherent drive to be the best that we can be, and to accomplish all that we are capable of accomplishing. Rogers and Maslow called this drive self-actualization . Interestingly, this concept is actually thousands of years old, and having spent time in China, Rogers was well aware of Buddhist and Yogic perspectives on the self.