Psychologist Theories free essay sample

Even though nature and nurture influence human behavior, nature and nurture work together equally in the development of human behavior because both genetics and environmental influences affect the outcome of a persons behavior and/or personality, while neither of the two traits can single-handedly determine ones behavior and/or personality. The question that has been pondered upon for many decades is which of the two (nature or nurture) are more influential? To illustrate: In looking for the causes of individual differences in intelligence, a major issue is the relative contribution of genetics and environment. 100% Genetics(Nature)90% Gen. 80% Gen. 70% Gen. 60% Gen. 50-5060% Env. 70% Env. 80% Env. 90% Env. 100% Environ. (Nurture) Rate the extent to which you believe nature and nature influence (cause) human intelligence. (Ridley, 1999) There is a question as to how nature and nurture influence behavior. All throughout history psychologists have been trying to figure out which of the two, nature or nurture, influence the development of human behavior and/or personality more and because of this particular question psychologists began to do intensive research. They did this by studying each of the two theories separately. One psychologist, Plato, campaigned nature while the other, Aristotle, campaigned nurture. The studies began with nature. Nature is defined as the heredity or biological make-up that influences the outcome of ones behavior and/or personality. Nature can also be defined as an individuals innate qualities. Some psychologists, like Plato, suggest that humans start out in life with some amount of knowledge. Nature provides us with abilities and traits like eye and hair color, skin color, and intelligence that is determined by certain genes that are embedded in each cell in the human body. Again, many psychologists, like Plato, believe that genetics ultimately take credit for the resulting human behavior. On the other hand nurture is Nature v. Nurture 3 defined as the environmental factors that influence the outcome of ones behavior and/or personality. Nurture can also be defined as ones personal experiences. Some psychologists, such as Aristotle, suggest that humans start out in life without any knowledge, but knowledge is gained through life experiences. These psychologists believe how a child or person is raised strongly influences human behavior. Many psychologists, like Aristotle, believe that human behavior and/or personality is a product of the environment. While each child is born with his or her own distinct genetic potential for physical, social, emotional and cognitive development, the possibilities for reaching that potential remain tied to early life experiences and the parent-child relationship within the family. (Weissbourd, Bernice; Grimm, Carol). To illustrate so statistics have been provided thanks to a researcher named Ridley (1999): â€Å"Concordance rates of IQ scores  ·Evidence from family studies provides the main supporting evidence from which arguments about the relative roles of genetics and environment are constructed. A large number of the study of twins rea red apart was undertaken by Thomas Bouchard of the University of Minnesota starting in 1979. He â€Å"collected† pairs of separated twins from all over the world and reunited them while testing their personalities and IQs. Other studies at he same time concentrated on comparing the IQs of adopted people with those of their adopted parents and their biological parents or their siblings. Put all these studies together, which include the IQ tests of tens of thousands of individuals, and the table looks like this: Same person tested twice 87%  ·Identical twins reared together 86%  ·Identical twins reared apart 76%  ·Fraternal twins reared together 55%  ·Biological siblings reared together 47% (studies show that reared apart about 24%)  ·Parents and children living together 40%  ·Parents and children living apart 31%  ·Adopted children living together 0% Nature v. Nurture 4  ·Unrelated people living apart 0% â€Å". Ridley, 1999, p. 83 [The number is a percentage correlation . Attach section from Ridley’s book There are many factors for both nature and nurture that contribute to the development of human behavior. It has been believed that family history, genotypes, and/or heritability as far as health is concerned (which can all be affected by genes) can predestine human behavior. A genotype can be defined as an individuals genetic inheritance and heritability can be defined as the extent to which variability in a characteristic within a group can be attributed to heredity. Genes have a direct connection to physical development. The question is how much of a influence do health problems, which are credited to nature, have on the development of human behavior? Additionally, physiological factors like neurotransmitters, brain structures, and hormones are influenced by genes. On the other hand do life experiences or environmental factors ultimately decide the outcome of human development? There are some theorists that believe environmental factors alone predestine human behavior. These theorists use the phenotype to support their claim. he phenotype can be defined as the overt expression of a individuals genetic inheritance, which may also show the influence of the environment. In fact, nurtures influences stem from factors such as: extended families and peer(s) experiences, parental, prenatal, socio-economic status, media, and marketing. So how much of an influence do environmental factors have on human behavior? A child is born with the potential abilit y to learn Chinese or Swahili, play a kazoo, climb a tree, make a strudel or a birdhouse, take pleasure in finding the coordinates of a star. Genetic inheritance determines a child’s abilities and weaknesses. But those who raise a child call forth from that matrix the traits and talents they consider important. (Buchwald, Emilie). Children missing their fathers tend to focus more on the medias preconception of the male role instead the being exposed the nurturing potential that the role may convey. (Gordon, 2004). To illustrate: Correlation of child-parent verbal ability scores. Nature v. Nurture 5 This graph shows correlations between children and their parents and adopted children and their biological and adoptive parents on verbal ability scores. Heritability intelligence It must be noted, however, that heritability is not pure genetic influence as the pre and postnatal environments must be taken into account. Heritability estimates based on comparing correlations between IQs of monozygotic (identical) twins reared together with IQs of dizygotic (fraternal) twins and siblings are likely to overestimate the genetic component because monozygotic twins share more similar environments both in the womb and out Nature v. Nurture 6  ·twins reared apart are not assigned at random to foster or adoptive parents since homes are selected purposely to with regard to characteristics of he child and characteristics of the family. This would partially account for the IQ correlations attributed to inheritance  ·twin studies may not be generalizable to the population at large as twins are more susceptible to prenatal trauma leading to retardation. The inclusion of retarded cases may increase the twin correlation in intelligence test scores. heritability indexes r efer to the population on which they were found at the time and is not applicable to an analysis of test performance between two population groups e. . ethnic groups.  ·heritability does not indicate the degree to which a trait can be modified e. g. even if the heritability of a trait, like intelligence were found to be 100% it wouldn’t mean it couldnt be modified. (Anastasi Urbina, 1997). After reviewing the pervious information common sense directs attention to the facts that indeed nature and nurture must co-exist and work together in the existence of human behavior. Because of these facts psychologists have begun to study behavioral genetics. Behavioral genetics can be defined as the study of the effects of heredity and life experiences on behavior. Nature alone cannot determine the outcome of human behavior and/or personality. Studies have proven that genetics alone do not determine or predestine health problems and that environmental factors play a role in the prevention or lack of prevention towards health problems or issues. And it is proven that nature exist because babies are born with the ability to express or communicate ( in their own way and language) that they want something or that something is wrong. This supports the theory, that Plato campaigned, there must be some amount of knowledge present at birth that provides proof of natures existence. In the same way, nurture alone cannot determine the outcome of human behavior. Environmental factors alone cannot sustain human behavior. It is a proven fact that not only environmental factors and/or life experiences contribute to the amount of knowledge gained in human behavior. Such as the baby from birth that is equipped with some amount knowledge, the baby must also so learn during its life span. Life experiences such as: trails and tribulations, parenting styles, living arrangements only work along with the nature factors provided. Nature, we are starting to realize, is every bit as important as nurture. Genetic influences, brain chemistry, and neurological development contribute strongly to who we are as children and what we become as adults. For example, Nature v. Nurture 7 tendencies to excessive worrying or timidity, leadership qualities, risk taking, obedience to authority, all appear to have a constitutional aspect. (Turecki, Stanley). In the same way, The theory, also called interactionism or dynamic developmentalism, suggests that traits are caused by a cascade of various factors, starting with DNA and going through various micro- and macroenvironmental signals or conditions that affect the final form of the trait. (Henderson, 2001, para. 1). For instance: Pendulum of opinion on Nature vs. Nurture through history The zeitgeist (the intellectual and culture flavor of a time and place) has swung back and forth over time with regard to the amount of influence that nature vs. nature has on human intelligence. Ridley (1999, p. 77) In conclusion, Genes and family may determine the foundation of the house, but time and place determine its form. (Kagan, Jerome). Nature and nurture must work together in the determination of human behavior. Thus, Science News (2003) reiterates that both nature and nurture play an equal role in the development of human behavior. To conclude, The route through childhood is shaped by many forces, and it differs for each of us. Our biological inheritance, the temperament with which we are born, the care we receive, our family Nature v. Nurture 8 elationships, the place where we grow up, the schools we attend, the culture in which we participate, and the historical period in which we live all these affect the paths we take through childhood and condition the remainder of our lives. (Wozniak, Robert H. ). Even though nature and nurture influence human behavior, nature and nurture work together equally in the development of human behavior because both genetics and environmental influences affect the outcome of a persons behavior and/or personality, while neither of the two traits can single- handedly determine ones behavior and/or personality.