Equal Environment Assumption Summary

Table 3-1 examines the correlations between selected characteristics for the identical twins separated at birth and the twins raised together. When compared to each other, they both have very similar brain wave activity, blood pressure and heart rate in the physiological characteristics. The Raven intelligence test was very similar, but the WAIS IQ displayed a bit of difference when compared to the other comparisons made. Personality wise, they typically had similar personalities at the same rate as twins raised together. Psychological interests were off a little bit, but still very similar. The twins that were separated at birth had less similar psychological interests compared to the twins

Throughout history, across all cultures, people have been fascinated with twins. In addition to interest in the close emotional ties and biological similarities that twins may share, reports of special twin languages and twin extrasensory perception (ESP) help people to explore ideas of what it means to be human. How similar or different are they to each other? How important are genes and environment for development? Because identical twins share all of their genes, it is the environment—rather than genetics—that accounts for any differences between them.

A strength of twin studies is that they are an example of a natural-occurring variable: MZ twins share 100% of their genes, whereas DZ twins share about 50%. As the researcher doesn’t manipulate the variables themselves, the risk of researcher bias is

In the podcast ‘Identical Strangers’ Explore Nature vs. Nurture, I initially thought that the study Elyse and Paula were subjects in was interesting because the twins were able to develop individually. Our book discussed how it is critical for twins to move from a sense of “we” to “I” (Santrock, 2017, p 68). This is exactly what Elyse and Paula were able to from an earlier age than most other twins because they were separate. Though they may have been able to move to the “I” more quickly, the twins missed out on 35 years of knowing and loving each other. They also did not get the opportunity to bond in a shared environment. The book states that “genes may be systematically related to the types of environment to which they are expose” (Santrock,

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

Most researcher study twins who have grown up together and carefully compare the experience of identical twins to those of fraternal twins. Comparing identical and fraternal twins enables researchers to separate genetic from environmental influences without measuring genes directly. The physical trait like hair colour is shared more often by identical twins than fraternal twins. In shorts, genes must have played a role in developing the traits. Twin studies provide most of the evidence that genes determine human traits and behaviours. For instance, genes influence such traits and behaviours as height, weight, manic-depressive psychosis, alcoholism, cognitive development, reading skill and so on. Environment factors unique to each individual

According to Saul McLeod in “Nature versus Nurture in Psychology,” nature is “what we think of as pre-wiring and is influenced by genetic inheritance and other biological factors.” Nature is our prewritten genetic code—genes determine physical characteristics like height, eye color, hair color, but genes can also determine personality. When studies based on nature are performed, fraternal twins are often studied; In “Nature and Nurture Debate” Sarah Mae Sincero states that “When fraternal twins are reared apart, they show the same similarities in behavior and response as if they have been reared together” (1). Even though the environment has changed, behavior stays the same.

Nature and Nurture I believe are very curtial parts of development that can have a very big impact on a child. In a nonhuman study scientist observed animals with similar genetic backrounds in different enviroments to determine the effects of specific environmental stimulation. Often times Life experiences can change parts of DNA that switch individual genes from on to off, alterations can be passed to future generations. When studying twins many things can occur, if the set of twins is identicle they are likely to act the same behavior wise due to their enviornment factors. While faternal twins are most likely not to act like their sibling at all. Children who live with their adoptive parents are weaker in association due to a high association

Q) Explain why twin studies such as this are used to study the nature and nurture theories.

Behavioral genetics is a branch of the study that researches and quantifies the effect of genes on humans. To conduct this research and determine what makes people uniquely different from one another twin and adoption studies are utilized. Twin studies consist of either monozygotic or dizygotic twins to evaluate the effects of hereditary on human development and behavior. Monozygotic otherwise called identical twins are developed form one sperm that fertilizes one egg, essential from one zygote that splits into two embryos and share 100% of their genetic makeup. Dizygotic are two sperms that fertilize two eggs and are fraternal twins that share up to 50% of their DNA (Belsky, 2013). To determine inheritability behavioral geneticists statistically

which they act. In the same way, the effects of the environment dependents on genes on with which they work .for-example people are very in height, although height is heritable but the environmental variable can have the large impact to it. An aspect of human intelligence and behavior have involved studies of twins, both monozygotic (identical) and (dizygotic (fraternal); cognitive or behavioral characteristics that entirely under the genetic control would be predicted to be the same or concordant, in monozygotic twins who share in identical.

In psychology, studies concerning identical twins have been performed, and the results have brought about proof that genetics are the larger factor in determining personality. The results of these tests showed that twins were twice as likely to have the same personality. This

Parents who dress their twins up in the same outfits or get them the same set of toys does not contribute to twins who have the same traits. It shows that a common environment does not give much impact in developing personalities. Mischel (1981) has also attested to this issue saying that genes and glands are different, but social learning plays a dramatic role. People develop vast differences through the stimuli they face in their daily life. Despite being reared in the same environment (their home), both twins could have had different sets of friends. Thus, going through their school years having different experiences and facing different challenges. As a whole they will have completely different hobbies and interests.

Who were the participants in the study? The participants in this study were two birth cohorts (1994 &1995) of same-sex twins and their parents from Wales and England. 56% were monozygotic and 44% were dizygotic twin pairs. The participants were members of the Environmental Risk Longitudinal Twin Study to study how genetic and environmental factor’s can shape a child’s development and specifically how a father’s role in his child’s life, (whether living with or away from the child and whether he is very antisocial or just a little) can affect the child’s own behavior and conduct. Out of 15,906 pairs of twins born, 71% joined the study. The children were all around the age of five as data was collected within 120 days of the twin’s fifth birthday. Several of the 1,210 families that were used in this study had to be excluded out of the findings due to them moving or them not being able to speak English.

A number of recent twin studies have shown that our genes, to a surprising extent, influence behavior. Even matters that naturally seem to be a reflection of one’s personal experiences, such as political stance or religious views, have been proven by various studies to be largely controlled by genetics (Times Higher Education, 1997). Researchers at the University of Minnesota launched the Minnesota Twin Family Study in 1979, in which over a period of 20 years, they studied 137 pairs of twins – 81 of which were identical. Through this study, researchers found that about 70% of IQ variation across the twin population was due to genetic differences among people (LiveScience, 2014); a more recent study in 2009 also supported this. Behavioural