Effects On Heritability And Environment : Twin And Family Studies

Identical twins are many times seen as genetic reproductions representing variations from twin to the other twin and are created because of environmental factors (Cervone & Pervin, 2010). Since identical twins share identical genetics, his or her personality seems to also share similarities. Moreover, the environment can impact fraternal twins, resulting in fraternal twins personalities and his or her characteristics similar to each other. For example, identical twins. Some research shows twins that are raised in the same residence have little differences from those who are raised in a different home.

There are no two individuals that are completely alike, people vary by hair color, height, skin tone, gender and other endless possibilities. The reason for these variations can be traced back to our genetic make-up. A person as 23 pairs of chromosomes and each of these chromosomes carry one molecule of DNA. DNA itself is made up of adenine, thymine, guanine, and cytosine, then, these chemical compounds wrap around each other to form a double helix. These chromosomes contain around 20,500 genes and even with such a large number our variations are caused by less than 1% of our genes according to the Human Genomes Project in 2003. These variations also come from genotypes and phenotypes. A genotype is the complete set of genes that make a person’s hereditary, whereas, a phenotype are psychological, behavioral, and psychological features that result from the interaction between genes and the environment.

Human behavior is a loosely defined foundation for individuality, generally considered to be influenced and developed by the environment. However, recent molecular studies have exposed genetic factors that suggest a more biological origin for behavior. Gene segments in the genome of humans and other animals have been identified and associated with particular behavioral traits. Is it possible that the presence or absence of even a single gene may predispose one to alcoholism, increased irritability, or enhanced intelligence? Clearly exploration of the nature versus nurture argument with regard to genetic predisposition has social, political, and legal significance.

A related phrase described by Waddington to help elaborate the phenomenon of epigenetics, the ‘epigenetic landscape’ attempts to explain how identical genotypes could result in a wide variety of phenotypic variation through the process of development. This epigenetic landscape can be dynamic – capturing genetic, environmental, and cell lineage effects – and has been shown to be at least partly heritable. (Szyf, M. (2015) Nongenetic inheritance and transgenerational epigenetics. Trends Mol. Med. 21, 134–144). The epigenetic code is hypothesized to be a defining code in every eukaryotic cell consisting of the specific epigenetic modifications in each cell. While in one individual the genetic code in each cell is the same, the epigenetic code is tissue & cell

A person’s nature, or genetics, determines aspects of the psychology of a person before they’ve been born. There are many example of how genetics determine characteristics of a person, regardless of the environment, also known as

The basis upon which behavior is determined and influenced is widely disagreed upon. Among some circles, it is believed that if behavior is determined by the biological process, then there is no basis for morality because an individuals behavior is a product of genetics. Others disagree, and suggest that behavior is determined entirely by nurture rather than nature. To properly understand how behavior is determined, the role of environment, genetics and biological processes in behavior, and the basis for morality, must be understood.

We all know that our genes are what give us our physical characteristics such as, eye color, hair color, the color of our skin, whether or not you’ll have freckles and how short you’ll be or how tall you’ll be. (pg91) Not only can our physical characteristics be determined from our genes but our behavior can be determined as well. Although it is more difficult to perform experiments on the human race, there has been some research that can prove whether genetics have any influence on the behavior of a human; to do so they performed research that would allow them to separate genetic and environmental influences. This research, kind of hits close to home for me because they did a study on twins,

In the modern age, genetics, the study of heredity and inherited characteristics, is a rapidly developing field of science which has provided major advances in the

During the second half of the 20th century, psychology was dominated by the behaviorism theory which states that all human behavior is controlled by environmental factors. Adopted monozygotic twins who were separated at birth were to be reunited later on as adults. The purpose of this study was to see if monozygotic twins that were raised together (MZT) were more similar than monozygotic twins that were raised apart (MZA). The twins each had one week visit, testing about 50 hours every week. These tests included four personality trait scales, three aptitude and occupational interest inventories and two intelligence tests. Along with these tests, there were interviews that were held. These included a life history interview, a psychiatric interview and a sexual history interview. All the assessments that were done were held individually so that the twins did not influence each other’s answers.

The Minnesota Twin Study is a correlational study which seeks to establish the relationship between genetics and/or environment on personality. The study uses twins as a basis due to shared genetic material. The two types of twins, who were separated at birth and raised in different environments, are the (adult) participants; the data accumulated from these twins was compared to the control

An individual’s physical features can be identified as identical to the one that resembles his or her parents. The resemblance may feature the individual’s eyes from one of the parents. However, it is important to note that the personality and the talents of the individual may not be identical from the parents. This means that the environment in which the individual grew up may play part in the individual to have the talent or the personality. I believe that our behaviors are influenced by the environment that surrounds us. This because as the cultural aspects are changing, so as our behaviors changes too (Gander, 2003). It is important to note that the coding of the genes in each of the cell in the human beings is determined by the different

According to McGue (1998), the nature of genetic and environmental influence on individual are differences in cognitive ability, personality and interest and

Is behavior learned? It is inborn? What of aggression, intelligence, and madness? There is a crucial relationship between the behavior of humans toward their own kind and the view of life they hold. Interest in behavioral genetics depends on wanting to know why people differ. According to Jack R. Vale, in Genes, Environment, and Behavior, recognition of the importance of hereditary influence on behavior represents one of the most dramatic changes in the social and behavioral sciences during the past two decades. A shift began toward the more balanced contemporary view that recognizes genetic as well as environmental influences on behavior. Behavioral genetics lies in its theory and methods, which consider both genetic and

Heredity – the transmission of traits from one generation to another, from parents to offspring; the protoplasmic continuity between parents and offspring

Genes build the phenotype of humans as well as the underlying genotype. Competition between cultural genes leads to varied success of genetic determinism. It can therefore be said that learnt traits such as those espoused within a specific culture, can produce what may seem to be the genetic genotype of an individual. Genes are not always advantageous in the