Theory Of Personality Essay

A key question for personality psychologists is: “Are we what we are because of nature or because of nurture?” When the question is phrased in this manner, neither answer can be correct, for the answers are not mutually exclusive. The premise of the question itself is wrong. We are what we are because of how nature and nurture interact; it is not a question of either/or. There clearly are both inborn and social-cultural influences on the individual. Genetics and environment—nature and nurture—regulate and guide each person. Theory Of Personality Essay

In Chapter 1 we examine some of the innate determinants of personality and behavior. We observe that, as products of a long evolutionary history, hu- man beings are predisposed to certain patterns of behavior. In addition, spe- cific genetic blueprints provide the foundation for personality and behavior.

But it is evident that individuals’ personalities are greatly influenced by the contexts that surround them and by the experiences they have had. Individu- als brought up in different cultures or social classes behave differently. If one wants to predict what an individual is doing or thinking at a given time, some of the best predictors are the point in history when the individual was born and where he or she is living. In Chapter 2 we examine some of these social and cultural influences as well as other kinds of environmental influences.

Culture not only influences individuals; it also influences psychological the- ories themselves. There is increasing reason to believe that the “grand theories” of Western psychology reflect certain biases about the nature of people that characterize Western culture.

Chapters 1 and 2 do not attempt to give complete accounts of the genetics of personality or the social determinants of action; full courses are devoted to these topics. Rather, we introduce the context of the person: an individual with unique predispositions who is nevertheless modifiable and shaped by surroundings.

Innate and Environmental Determinants of Personality 1PART

CHAPTER 1 Genetic Determinants of Personality

CHAPTER 2 Contextual Aspects of Personality and Behavior

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Genetic Determinants of Personality

Charles Darwin introduced the idea that the human species is the product of a long period of evolution in The Origin of Species and Descent of Man. His arguments had an enormous influence on the field of personality. First, his theory of evolution assumed scientific determinism—that is, the theory assumed that the most complex aspects of behavior in all species are sub- ject to scientific and rational analysis and are not due to accident or divine intervention. This principle was accepted by psychologists in their study of both nonhuman and human behavior. Second, Darwin focused attention on the function or adaptive value of biological structures and behavior. Psychol- ogists have been guided by this viewpoint as they search for the usefulness of a particular pattern of action. Still another implication of Darwin’s work for the study of human personality is the importance of species differences and of individual differences within species. These issues are addressed in this chapter.

Darwin proposed a simple yet powerful theory to explain the process of evolution that linked the development of species with the concept of inheritance—the transmission of characteristics from one generation to an- other. He stated: “Any variation, however slight and from whatever cause proceeding, if it be in any degree of profitability to an individual . . . will tend to the preservation of that individual, and will generally be inherited by its offspring. The offspring, also, will thus have a better chance of surviv- ing” (1869, p. 61).

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CHAPTER1 Chapter Outline All Humans Are Alike All Humans Are Unique

4 Part 1 Innate and Environmental Determinants of Personality

Nearly every theory of personality tries to describe why people are the way they are. Personality theories are going to make the claim that all humans are alike and the propositions apply to everyone. Simultaneously, personality theories are going to try to explain why each human is different. In our exploration of the influence of genetics on personality, we will see this fully on display. We will start with the ways in which we understand how people are alike, and then we will explore the ways in which people are unique.

In this chapter we examine some of the genetic determinants of personality structure and behavior. Although neurotransmitters and hormones, brain mechanisms, and other biological factors influence personality, we focus here on the topic of genetics because of the vast research in this area and because it well illustrates the role of biological givens in behavior.

It is helpful to frame a genetic approach to personality within the context of evolu- tionary theory. Among the questions we discuss in this chapter are: What limitations do inherited characteristics place on learning? Do humans have instincts, or innate urges and unlearned patterns of behavior? Are there universal facial expressions or behaviors that are exhibited across cultures? And can it be demonstrated scientifically that person- ality characteristics and behavioral problems are in part genetically influenced? We will present evidence that the answers are yes and that a complete theory of personality must consider innate factors.

All Humans Are Alike The human genome is made up of 23 chromosomes, which are then made up of a molecule called deoxyribonucleic acid (DNA). DNA has four bases: adenine, thymine, guanine, and cytosine. These are often denoted just by their first letter: A, T, G, and C. These four letters provide the instructions for mak- ing amino acids that then make up the various proteins and en- zymes that make up living organisms. The process by which this happens is beyond the scope of this book, but it is important to understand some of the basics.

DNA is copied via another molecule called ribonucleic acid (RNA). In the process of copying, mistakes can be made. Fur- thermore, mutations can also occur due to exposure to radia- tion and other things in the environment. Most of the time, the mutations are harmless; some of the time, the mutations are harmful. Importantly, sometimes the mutation leads to positive outcomes and increases the chances of the organism or its off- spring surviving. Theory Of Personality Essay

Through the instructions on how to build the amino acids and how to arrange the amino acids into proteins and enzymes, the DNA provides the information needed to create brain struc- tures, neurotransmitters, and hormones. These then become the building blocks of behavior. All humans have a genome that codes for these things, but there will be subtle differences among each person, as everyone (except monozygotic twins) has a slightly different genome. However, unrelated humans still share somewhere between 99% to 99.5% of their DNA. The general pattern is what makes us human and will therefore make us similar in many ways.

It is important to recognize that most of what we will be examining will not be the result of a single gene, but rather

Our DNA is made up of four molecules: adenine, thymine, guanine, and cytosine.