Summary: The Minnesota Study Of Twins Reared Apart

Many psychologists agree that nurture play a greater part in the development of a human being. Studies such as those performed on monozygotic twins (identical), who share the same genetics and those performed

“Trying to separate out nature and nurture as explanations for behavior, as in classic genetic studies of twins and families, is now said to be both impossible and unproductive” (Levitt, 1). Social scientists have declared the nature-nurture debate to be unnecessary. Similarly, scientists feel that such debate is not only unhelpful, but also outdated. From geneticists’ perspective, nurture and nature interact to influence

The idea that they came up with was finding identical or fraternal twins in order to draw a comparison between the behaviors that they share. The most common similarities between the twins (after multiple meetings with pairs of twins) can be concluded as genetic, and other factors could be considered due to the environment, like learning a language. In 1983, Bouchard and Lykken brought together these twins who participated in the study. First, they needed to gather identical twins who were separated at birth. The researcher 's’ goal was to gain as much information as possible on these twins within one week. They had fifty hours of studies on many levels. These studies included personality trait scales, aptitude, IQ tests and occupational interest tests.

Twin studies are a mainstay of the nature verse nurture debate because they allow researchers to conduct “natural experiments” on human beings. When researchers try to determine the relative importance of genetics and environment with regard to a certain condition, they have a hard time because they cannot generally get people with the same genes. This is where twin studies come in. Twins studies are part of the method used in behaviour genetics, which includes all data that are genetically informative. E.g. siblings, adoptees, pedigree data etc. Researchers use this method to estimate the heritability of traits and to quantify the effect of a person 's shared environment (family) and unique environment (the individual events that shape a life) on a trait.

The Minnesota Twin Registry started in 1983 and its goal was to establish a registry of all twins born in Minnesota from 1936 to 1955 to be used for psychological research.., T.J. Bouchard, working in conjunction with the University of Minnesota, started exploring the similarities and differences in characteristics like personality, career interests, and a variety of personal interests between identical twins who were reared apart. Research was conducted on twins from all over the world. The Minnesota Twin study gave scientists a new insight of the role of nature vs. nurture on human development and personality; it was the hope that twin studies would be able to tie genes to specific behaviors. From the study, we understand that twins who were separated at birth and raised in different families

In reading stories about identical twins my point of view is easily understood. Various types of psychologist have analyzed the study of identical twins. It shows that individuals with the same genetic make-up can be totally different, when it comes to personality. Nurture promotes the twins to grow up as separate individuals. Its a lot better if a twin has his or her own personality rather than the same exact personality of the other half. I think this great debate weighs heavier on the nurture side. As a child my parents, and sibling overshadowed my genetic make-up. No matter how much I thought my physical traits made me behave. It did not affect me more than the things that I had seen and been exposed to. The more things that I had seen around and experienced made me the person that I am today. If my genetic make-up was totally different, to a certain extent, I am sure that I?d behave the same way that I do presently. There are exceptions to that. For instance if I were six foot five and one hundred and ninety pounds, I?d most likely be in the NBA and be really rich. I think if I was really rich and in the NBA I wouldn?t have the same worries that I have today. Even if before I were in the NBA I would have lots of attention and have a lot more confidence. So to an extent I would change a little if my genetic make-up were different. In a sense, genetic make-up is just a competitor to the environmental factors

The nature- nurture debate has many different case studies, which often questions environmental and hereditary aspects of the nature- nurture debate. A tangent which is focused on in this essay is how the case studies of schizophrenia and IQ, specifically affect twin and adoption studies. This essay will firstly, give a brief outline of the nature-nurture debate and the definitions of twin and adoption studies. Secondly, it will illustrate two main case studies, which are IQ and Schizophrenia studies. Thirdly, will contrast and compare the two and research’s impact on the case studies in regards to nature vs. nurture and finally, will conclude with the impact of the nature-nurture debate and twin and adoption studies.

The main focus of this study is whether nature or nurture is stronger. The researches wanted to see if twins who were separated at birth would still grow up to be similar. I believe the results will be that the twins will share some interests and similarities, like all siblings do, but because of the separation they will not be as similar as that might have been if they had been kept together. From my experience, people are born with a personality. There are certain traits that we are born with that the environment we grown up in can influence, but cannot completely change. With that said, the environment we grow up in does play a large role in the people we become and what are opinions are. As we talked about with the sociological imagination, outside influences make a huge impact on our

According to Begley, identical twins are not always identical in behavior just because of genes. Some studies show that when twins are given different circumstances, for example, different educational opportunities, different results are obtained. One example in Newsweek showed one twin may grow to be a professional pianist while the other twin was not at all musical even though the twins were both raised in a musical environment ("Heredity" 69). Twins have different interest from each other, and express them in individual ways.

Richard M.Ryckman , Theories of Personality, Ninth Edition. 2008, 2004 Thomson Wadsworth, a part of The Thomson Corporation

As stated by Myers (2007), in the above quote, adopted twins studies also play a role in determining levels of intelligence and its heritability. However, like in all other psychological testing, correlation does not always mean causation and atypical findings may find their way into the data poll. It must also be noted that in order to successfully foster an identical twin study, all the twins should be adopted. This provides for a better chance for the twins to grow up in a different environment from their biological parents. If this is not the cases, how can professionals determine that environmental influences are not the cause of the intellectual levels? In addition, if separated,

Another study that has been done was with separated twins. Each twin was raised in a completely different environment than the other. Genetically, they were both identical in every way, but the environment that they were raised in was very different. One twin was raised in a very hostile setting and slowly became violent as an adult while the other twin was

Another study carried out on twins, were twins separated at birth through adoption. The studies wanted to see if growing up in different environments with different families had any impact on whether or not the twins grew up to be deviants. (Blackburn, 1993a) Psychologists wanted to work out if there was interaction between the environment in which they grew up in and their genes. Schulsinger (1972) carried out the first adoption study in Denmark. His theory was to compare adopted adults, some adults had been diagnosed as psychopaths and others hadn’t. There was a lot of criticism regarding his theory because Schulsinger used his own criteria to diagnose particular adults with psychopathic behaviour. Another criminologist who developed a theory around adoption was Crowe, he studied those that came from families with criminal backgrounds, but had been raised with a different family through adoption. Crowe wanted to analyze the results and see if there were any connections between your parents offending and you growing up to be an offender, even if you were raised by other parents with different values. Chemical and hormonal imbalances, bran injury and brain dysfunctions are other biological explainations of crime.

Scientists and psychologists everywhere study twins. The argument most commonly studied is nature versus nurture. The focus of this essay, however, is whether or not to separate twins in schools. Some believe the separation is demeaning and traumatic to the twins. The side about to be proved however that is this separation is a necessary step in the individualization of twins. Often, separation sparks the path to individualization.

From these studies, researchers have found that twins who have grown up in the same household share similarities in the way they think, act, dress, speak, etcetera. However, with the first type of twin studies, researchers could not differentiate whether the similarities were due to them having identical/similar genetic makeups or growing up in the same environments. Therefore, in order for psychologists to know whether similarities in twins are genetic or socially influenced, they studied twins who grew up in completely different households and environments. The study showed that despite growing up with a different family and in a different environment, they still had noticeable similarities in fashion, interests, and thought processes (K.W. Brown, personal communication, August 29, 2017). Twin studies, as well as other studies, have greatly contributed to our understanding of overall role that genes play in the development of psychological traits and behavior.