Behavioral Genetic Study

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

Genetics and behaviour Over the years it has been argued that behaviour is affected by genetics, this is nature vs nurture. One study that shows the nature side of this argument is an adoption study, Kety and Ingraham who were twins and adopted both had schizophrenia. This was compared to their biological family and their adoptive family; it was found that the chance of having schizophrenia was ten times greater from the biological family than in the adoptive family. This case study shows how genetics can determine some behaviour and supports the nature argument.[1]

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.

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

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 claim of the day was that genetic factors play a strong role in human development that genes alone can determine certain human behavioral characteristics. Plomin focused on behavioral genetics in the 21st century. He discusses quantitative genetics and molecular genetics along with three different directions for genetic research such as developmental genetics, environmental genetics, and multivariate genetics. The greatest need for quantitative genetic research going beyond heritability is asking how much genetic factors are important in behavioral development. The three different directions of

Twin studies have been a large part of the growing debate on whether genetics or environment (nature v. nature) is responsible for the cognitive, socio-cultural and biological development. In order to properly assess twin studies it is important to know why and how they are relevant in psychology. Identical twins are especially effective in research particularly in the field of developmental psychology and behavioral genetics due to the monozygotic genes which means they originate from a single zygote (fertilized egg) which essentially means they share 100% of the same genes. Due to this exact copy of genes between twins means this can be efficiently be used in order to observe the impact of

Many researchers argue whether genetics or the environment, play a greater factor in the future behaviors of children. Some articles did experiments which indicated nature is a strong possibility in children’s behaviors; while the opposing articles experiments showed that nurture is also a strong determinant. The goal for this paper is to show how genetics and environment both affect a child’s behaviors.

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.

The world of Genetics is one that is both fascinating and interesting. When tackling how genetics plays a role in behavior, one must look within the scope of what genetics is before dealing with how it plays a significant role in one’s behavior. Simply put, genetics is the study of genes. It is a biological component within the entire study of biology itself. Scientists who study genetics and perform research do so with the intent to learn more about how genetics affects the overall attitudes, behaviors and dispositions of individuals. It could be said that genetics is somewhat of a psychological-biological science as researchers look at the underlying patterns within the genes that cause

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

Across studies of 10,000 twins, the intelligence test scores of identical twins reared together are virtually as similar as those of the same person taking the same test twice…Likewise, the test scores of identical twins reared separately are similar enough to lead twin researcher Thomas Bouchard (1996) to estimate that ‘about 70 percent’ of intelligence score variation ‘can be attributed to genetic variation. (p. 455)

However, genetic hypotheses should also be considered. Research in behavioral genetics is directed toward understanding differences in behavior. Methods are employed that consider both genetics and environmental influences, rather than assuming that one or the other is solely important. Behavioral genetics research studies whether individual behavioral differences are influenced by hereditary differences. Then, estimates the relative influences of genetic and environmental factors. Although genetic and environmental influences interact within an individual, this does not imply that the separate effects of genes and environment cannot be untangled when we focus on differences among individuals

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

Some psychological models assert that a proportion of our personality is inborn and permanent (Hollander, 1971), that a psychological core at the center of our personality gives us enduring, inner characteristics. Hans Eysenck (1965) suggests that our motivation and emotion are related to biological differences in brain function and proposed that 75% of our personality is based on genetic influence and 25% on environmental influence. Research by Peter Whybrow (1999) on identical twins separated at birth examined how their different environments shaped their personalities. He found that around 40% of personality should be credited to genetics, with 60% determined by outside factors.